Dumpers Part IV, Segment B: Nautilus and Life Fitness

41 comments written by Joshua Trentine

The Nautilus/Organ/Sencil Leg Extension

Most of the following depends on the memory of Ken Hutchins. We welcome any details that might be improved from others who witnessed the use of this machine:

During the last few years at the Jones-controlled Nautilus Sports/Medical Industries, INC., Arthur Jones directed almost daily demonstrations on a prototype Leg Extension developed by Dr. Lesley Organ and Phil Sencil. (Phil later became the design engineer for MedX after Arthur sold Nautilus to Travis Ward in mid-1986.)

Reportedly, this machine cost Nautilus over $6 million to prototype over a period of several years. Once it was reliably functional, it was set up in the pavilion at Jumbo Lair in Ocala, Florida, and Arthur demonstrated to visitors as one of our strong employees acted as subject. The subject was almost always Jim Flanagan.

This machine employed some kind of brake motor (Only Phil Sencil could accurately describe this.) that was preset at a constant movement speed and preset at a predictable turnaround point (range of motion) at both ends of the excursion. It resisted against knee extension of only one leg.

It provided no back pressure during the positive. In this regard we classify it as a pure isokinetics machine.

It provided a precise graphical feedback via a monitor for the subject. The feedback displayed position on the horizontal and force on the vertical. The graphical trace conveniently enabled the contrasting of the force between negative work and positive work.

This machine enabled—did not require—the subject to push with maximum effort during the positive by trying to make the movement arm move faster. No matter the effort or force from the subject, the movement-arm speed remained constant.

During the negative the subject was able—not required—to apply maximum effort to slow or stop the movement arm. Of course, the movement-arm speed remained constant.

Ken Hutchins neither promoted nor condemned this machine. He considered it an interesting research tool—perhaps valuable. At that time, he privately considered that it would lead to the future of strength training, but could not envision how it might be made practical and available to anyone without a few million to put down. However, he deplored the macho presentations by Jones. The speed of movement was recklessly fast and revealed that Jones and the engineers could not appreciate the 10/10 protocol that was being used in his own osteoporosis research project just 40 miles up the road in Gainesville.

Meanwhile, Ken could perceive that nothing was being done to correct the exorbitant friction in the Nautilus products. Ken asked himself, “All this high-tech stuff portends a great future, but can’t we at least correct the weight-driven machines that we presently sell?”

Ken’s last memory of this machine was that Jim Flanagan’s shin became so bruised from the presentations that Tom Laputka was called in to substitute. Supposedly, Tom damaged the machine and it was temporarily out of use.

Looking back, we see the inherent problems with the application of such a device. In theory, it might be useful, but only if the subject can be guided to avoid maximum effort during the early repetitions. This caveat applies to the entire repetition, but especially to the negative. What constructs might be necessary to effect this and to effect this for different subjects with different joint issues is complex and problematic—perhaps impossible.

And once we saw the mechanics and electronics of this Nautilus prototype—or those similar—put into use in products like the Exerbotics, Ken’s allowances for negative hyperloading began to turn.

In April 2012, Ken visited with the wife of a quadriplegic. He seated her on a desktop and asked her to pretend that she was her husband trying to extend his knee. She responded that the physical therapists had pronounced the musculature “dead’ because nothing happened.

Ken then lifted her lower leg to extension and carefully released it for her to lower as though performing a negative-only excursion. Ken asked, “What happens when he tries to lower after it is lifted for him?”

She responded, “His muscles do show some tension.”

Ken exclaimed, “Therefore, it is not ‘dead!’ And if it is treated as ‘dead’ for several months and years it may become really ‘dead’ due to neglect!”

Negative-only has an important place in early-stage rehabilitation with some populations. But it is being abused by many of the HIT people—especially those enamored with the Dumper machines.

This concludes our opinions regarding The Nautilus/Organ/Sencil Leg Extension.

Life Fitness

Our first experience with commercial equipment designed to perform negative hyperloading was the Life Circuit by Life Fitness. When we first encountered this approximately 20 years ago—it seemed clever and very high-tech, but only to the degree that the Life Fitness people seemed to have swallowed wholesale Nautilus’ faulty publicity on the value of negative hyperloading. The tool demonstrates that technology is no smarter than the premise upon which it is based.

Every machine in the Life Circuit line possessed poor body mechanics. Of course, almost every manufacturer advertises that their body mechanics are topnotch when no one in the company knows what that is.

However, our main interest with the Life Circuit devices is the feature wherein the subject might elect to increase negative resistance to a magnitude greater than the positive—i.e., apply a hyperloaded negative.

These machines had these associated defaults for the hyperloaded negative:

Leg Press—15%

Triceps, Chest Fly, Back, Abdominal, Overhead Press—25%

All others—40%.

The Leg Press had such a low percentile increase because of the limitation of the DC motor that provided the resistance.

These machines did provide a negative backpressure during the positive (unlike the Nautilus/Organ/Sencil—NOS—prototype, the Exerbotics and the CZT/ARX machines).

The standard presets could not be changed by the user; however some of the defaults could be changed by someone with programming skills. We have associates who are consulting the owner’s manuals regarding these values, but the exactness of our numbers are not critical to our basic stance that equipment with negative hyperloading is a mistake.

Another memory we have of the Life Circuit line is that when performing the 10/10 protocol, the resistance supplied by the machines was erratic. We felt the machines surging as though our slowness of movement confused its sensor. The machine also beeped repeatedly if we moved too slowly. We are now told that this might be adjusted out. Again, all of this is moot. It was a ridiculous concept run amok.

This concludes our opinions regarding Life Fitness/Life Circuit.

{ 41 comments… read them below or add one }

avatar marklloyd June 15, 2012 at 11:58 am

“… it might be useful, but only if the subject can be guided to avoid maximum* effort during the early repetitions…” I recently posted about my required 7 to 10 seconds of tension build-up before I can begin movement on 10/10 rep1 w/MedX Lumbar. (My other exercises all require less, but -some- build-up.) My point was that if a machine moves on its own, such build-up hasn’t yet occurred. Thus, it’s fair to assume: 1/ *maximum effort on the early reps be unlikely for average subjects , 2/even equalling the effort required to begin a weight-resisted 60-90 second set of 10/10 is doubtful.


avatar Doug McGuff, MD June 15, 2012 at 12:05 pm

Strange. Check out the latest comment I left on my blog moments before I came over to see if anything new was going on at RenEx.


avatar tim June 15, 2012 at 12:53 pm

I always seem to find that it is imposssible to unifromly fatigue the muscle in every position of the range of motion. failure always seems to occur at the moment arm regardless of hyperloading the negative or any other type technique. They all miss the point that a muscle doesnt have to move at all to be fully stimulated?


avatar Mel Sanderson June 15, 2012 at 5:39 pm

The facility where I work out has recently added a complete lineup of the X Force Dumper machines. I have ignored them, as I have continued to train on the plate loading Med X Avenger machines. The Avenger machines have the least friction and are the best available at the facility for the 10-10 protocal.
I have noticed that it is usual for the new X Force machines to have a maintenance person to be working on them, and it is not uncommon to have more than one machine to have an “OUT OF ORDER” sign placed on them.
If only they had put in the new Renaissance machines!


avatar Joshua Trentine June 16, 2012 at 12:16 pm


I might be able to guess where you train :-)….anyway, yes the Avenger upstairs is by far the best gear in that facility to do some of the things we discuss. Just Fyi, leave the catch bumper in on the Avenger Leg Press and try to use the upper body machines with fused movement arms. I’m sure you are getting great workouts. If you ever go down stairs to toy with the X-FORCE we would love to hear your report.



avatar Scott Springston June 15, 2012 at 6:19 pm

Once again with the stores on how dumpers and old Nautilus wasn’t up to what Ken wanted to see. Interesting history but so what??When are you going to put forth as much effort to prove REN-EX methods and machines build muscles any better than Nautilus, hammer, cybex or barbells or whatever other methods and machines are out there??Show us some examples of some people who have built muscle using REN-EX ways. You can only knock other ways and brag on yourself for so long. Time for some proof!!


avatar Joshua Trentine June 16, 2012 at 11:33 am


I encourage you to actually read the Dumpers series. You will find that all of your concerns are addressed. You will also find that many of your points regarding our claims are inappropriate.

RenEx Team


avatar Joshua Trentine June 16, 2012 at 12:05 pm

(From Ken Hutchins)

Scott Springston,

As we have stated before, we do not presently possess the photos and data you request. Obtaining these properly takes time, preparation and rigid standardization. We will present such documentation later, but only if we can make it truly objective and reliable—something no one else has bothered to do.

I do not respect most other supposed data pushed onto the unsuspecting by this industry. I have experience obtaining supposed data for some of the same people who currently publish. I also have the skills and talent to “produce” amazing “results” with eye-popping comparison photography merely by putting muscular/overfat people on a crash diet and doing some hanky panky with the lighting—often without substantive modification of their workouts. So what?

I particularly like the title of the book, “Muscle, Smoke and Mirrors’ by Randy Roach. It perfectly represents the hucksterism replete in this industry.

And when we do get around to presenting data, we will also explain the “rubber ruler” effect—explaining how suckers are created with data and photos—especially photos.

It is natural and deserved to question anyone’s authoritative criticism of products when they make statements within the context of “having something to sell.” What is often missed; however, is that one is not considered authoritative about exercise equipment unless he works at building and selling exercise equipment. We are in a catch-22.

Nevertheless, note that our desire and discussions to attack the dumpers, including the selection of the name, “dumpers,” began several months before the formation of Renaissance Exercise and before the commencement of prototyping the new RenEx equipment and before the advent of the X-Force into the United States.

The primary aim of our Dumpers series has not been to directly address their efficacy at producing worthwhile results, but, moreover, to address the bad thinking that supports negative hyperloading. And to this primary aim, we have either proven and/or corroborated every assertion we have made thus far. What’s more, these assertions hold true if I had never been born, if there had never been SuperSlow, and if there had never been Renaissance Exercise! If a one-eyed, one-horned, flying-purple-people eater had made the same assertions their central argument would still be true!



avatar Scott Springston June 18, 2012 at 9:33 am

I also know how muscle building studies and programs designed to show how clients gain on certain routines can be very misleading like the Colorado experiment. It proved nothing except that Casey could regain his former strength if he trained hard and ate like a pig. The results of most experiments like the X-Force experiment are suspect at best as far as results are concerned because of so many variables that can’t be accounted for but I think there is a time for talk ( books, articles) and a time to show some kind of evidence that what you are promoting actually works. It’s obvious you have several trainers like McGuff or Baye who seem to like your system. To be perfectly frank that could be because they want to become part of the REN-EX team to make a buck at it, who knows? I’m not hearing from any serious bodybuilder who isn’t attached to REN-EX who raves how the REN-EX way is superior at building muscle. We who want to believe in REN-EX are tired of the talk and books and articles. We want to see something in the way of results that prove to some extent, even if it isn’t perfectly scientific, that what you guys are preaching is true. Personally I put more stock in what seasoned bodybuilders say about systems than any study or experiment. Get some real bodybuilders who have been around the block who have nothing to gain from trying REN-EX but muscle and have them do it for 6 months and have them report what they honestly think of it in comparison to other methods.


avatar Joshua Trentine June 18, 2012 at 4:16 pm

Hi Scott,
We could care less about “getting” seasoned bodybuilders to do anything. That being said I’ve trained plenty of them in the last few years, unfortunately there is no amount of “proof” to ever satisfy you…. I think you should read the articles again….slowly this time.



avatar Scott Springston June 19, 2012 at 9:10 am

Proof? You haven’t given one shred of proof so far that the system you advocate works any better than old Nautilus systems or anything else. You give loads of talk about how wonderful the REN-EX system and machines are but nothing more. I can only guess that you don’t want opinions of seasoned bodybuilders because they might not tell you what you want to hear. Even if I had all the books you or Ken have written that is only words on paper and nothing more. That only goes so far.You won’t convince anyone of anything with just words on paper. Remember how Arthur wrote that the pullover would be the upper body squat and that it was a “game changer” and how Nautilus would build muscles where muscles hadn’t been built before?? . Well it sounded good but never rang true. Just as big if not bigger muscles were and are built with barbells . It was just talk, like all of your talk. Where’s the beef??

avatar Tom Sesny June 18, 2012 at 5:58 pm

Scott –

If you are a “serious BodyBuilder” why not try the Ren-Ex system and equipment yourself? Then you can either agree or disagree with the equipment and system based on your own testing, rather than relying on what someone else has to say. Arguing without testing it yourself is pointless. I didn’t believe in the equipment or system when I first heard about it. Then I broke down, tried it, and my only regret is that I didn’t try this sooner. I am no longer a “serious bodybuilder” due to the injuries I sustained in the mid-80’s. For 20 years I aggravated those same injuries over and over to the point I could no longer bench an empty bar. Then I met the guys and Ren-Ex and after a year and a half of training this way I am feeling like I did when I was in my 20’s. Had I not tried this myself and merely listened to what the promotors and detractors of the Ren-Ex system had to say, I would still be a fat ass with bad shoulders, elbows, knees and back. Thankfully I found this system and it changed my life.

Josh and Ken, keep up the good work and don’t let the detractors bring you down. I am living proof that your system changes lives and there are a lot more of us ex-serious bodybuilders out there who need you and your protocols and based on the comments from Scott, there will be a lot more coming your way in the future.



avatar Scott Springston June 19, 2012 at 8:56 am

Why not try the REN-EX system? I don’t live in Ohio for starters.

avatar Joshua Trentine June 19, 2012 at 2:16 pm

Just FYI Tom isn’t just giving lip service, he left his law practice to open Intense 22 in Austin Texas.

And Thank You Tom, the detractors don’t bother us, no matter what we move forward. All of the response we get is feedback and anything that draws this level of attention, both negative or positive, must be challenging the status quo.


avatar John Parr June 18, 2012 at 9:35 pm

A real serious bodybuilder who needs to learn how to train and rest the way the protocol calls for! Intelligent enough to understand and apply it. I’d like to meet one.


avatar Joshua Trentine June 18, 2012 at 10:11 pm

nice to meet you John 🙂

avatar John Parr June 18, 2012 at 10:21 pm

Pleasure to make your acquaintance.

avatar Patrick June 16, 2012 at 12:23 am

“Interesting history but so what??”

I think this series of articles has been very informative for those of us who do not know the history of dumpers.


avatar Joshua Trentine June 16, 2012 at 12:46 pm

Thank You Patrick


avatar joel waldman June 16, 2012 at 6:21 am

I’m looking forward to your comments on the motivator…my Belmar fitness is probably the only gym in the country to possess one of these devices…I have used it since 1994 with excellent real world results…at one point becoming strong enough to stop it for as much as ten seconds in the mid range of the lat pulldown(831lbs minimum force required to stop the hydraulic)…this machine has a number of invluable features required for progressive loading including a visual display of prior workouts which you are trying to exceed…In 18 plus years I have never incurred an injury using this machine…and I have benefitted greatly from it’s use in terms of strength and muscular endurance. At my strongest, I could only do all out max exertions once every two to three weeks or I would stagnate or go backwards. I would be happy to contribute my “dumper” side of the story for your readers concerning this machine and other negative techniques we have used since 1073;;;Joel Waldman


avatar Joshua Trentine June 18, 2012 at 7:09 pm

Let it be perfectly clear without hesitation or doubt that the demonstrations on negative training as indicated on YouTube by trainees at Belmar are the categorical antithesis of everything we have been talking about since the inception of Renaissance Exercise. If you want to see precisely what we say you must never do in exercise, please go and watch this: http://www.youtube.com/watch?v=H-cm0orLnZg

For anyone who DOES engage in this sort of activity, please DO NOT POST COMMENTS ON OUR SITE. If your training consists of such antics, you are welcome to continue them and we truly wish you best of luck in your fitness goals.

I reiterate: We have zero interest in discussing such exercise praxis and we will not entertain further discourse on the subject.

The RenEx Team


avatar joel waldman June 19, 2012 at 9:10 am

“My mind is made up…don’t confuse me with more data”….boy you guys are self righteous…you take pot shots at various pieces of equipment and yet don’t want to hear from someone who has more experience with one of these pieces(Motivator) than anyone with the possible exception of the inventor Jan Miller(who I was close friends with for a period of at least 10 years from 1994 to 2004. My post was well written…non confrontational…and well intentioned…and you guys chose to dismiss me and my real world experience and observations without even a querry. One of your faithful…John Parr has used the motivator…performed perfect 10/10 superslow reps on it and related to me just last night that he remembered it well and was looking forward to another session this summer…he at least has some intellectual curiosity. But alas, a man convinced against his will…is unconvinced still…and you guys are “convinced”…be well…Joel


avatar Joshua Trentine June 19, 2012 at 2:11 pm


Appears to be opposite and completely unrelated to anything we’re doing.



avatar gus June 19, 2012 at 6:38 pm


You’re absolutely right that in this particular case our minds are made up. But realize that it is from the perspective of protocol intent, not the idea that a particular piece of equipment is “bad” or “wrong”.

If i decide I want a new motorcycle and decide flat out that I am after the allure, design, feel, and style of a cafe racer, a cruiser is just not in the running, no matter how well made, well-priced, or comfortable.

Your post is indeed non confrontational and well written but the fact of the matter is that the entire RenEx concept is actually founded on protocol that is diametrically opposed to the style of performance that you’re demonstrating.

I appreciate your success and say kudos to you for your achievements. But there is absolutely no relationship between what we are suggesting and what you are doing.

Best regards,


avatar Dean Curtis June 19, 2012 at 7:32 pm

But what about our Arnold cheat curls whilst screaming at the top of our lungs, sweating on the equipment, while we look in the mirror as our buddy gives us a shot of dianabol in the bottom as the chicks admire us?
Brilliant bodybuilders, eh! 😛

avatar Joshua Trentine June 19, 2012 at 6:51 pm

I echo Gus’s point.



avatar Scott Springston June 20, 2012 at 11:23 am

Dean Curtis June 19, 2012 at 7:32 pm

But what about our Arnold cheat curls whilst screaming at the top of our lungs, sweating on the equipment, while we look in the mirror as our buddy gives us a shot of dianabol in the bottom as the chicks admire us?
Brilliant bodybuilders, eh! 😛

Yea, but it built big arms none the less!! Has anyone done the same using REN-EX???

avatar Tom Sesny June 20, 2012 at 4:40 pm

Scott –

I have gained 25 lbs of muscle and lost 45 lbs of fat during the past 15 months training only 2 times a week for 20 minutes each session. I also did a 180 with my diet so most of the fat loss was attributed to that. The muscle gain came strictly from the Ren-Ex protocol. I documented it by using the GE InBody 520 body composition analysis machine. That is the same machine used by the Cleveland Clinic so I know it is accurate.

In the 80’s I followed Arnold’s advice and saw the same kind of results. My diet was more strict then and I spent, on average, 15 hours a week in the gym. Now I spend 40 minutes per week in the gym. In the 80’s I suffered injuries on a regular basis. I have been injury free since starting the RenEx system.

So in my opinion, I would rather spend 40 minutes in the gym and 15 hours with my wife and kids instead of 15 hours in the gym and 40 minutes with my family. Either way I can get great results. I’ve never used a “Motivator” but I bet I could get great results with that as well. But for me, I know the RenEx protocol works, it does so efficiently and safely, so that is what I do. Unfortunately, it appears you don’t have access to the Ren Ex equipment but you can still follow the RenEx protocol. Do yourself a favor. Buy Ken’s book. Follow the protocol with the machines you have access to in your gym, and enjoy all the free time you will experience, and in 3-4 months you will be wondering why you spent so much time arguing on this board.


avatar Trixie May 18, 2016 at 8:12 am

Jacque! I am right there with and why must people call their children mixed! That only makes people like over it refer to these children as dog!sWhat is the real reason that we are here???


avatar Anthony June 16, 2012 at 9:11 am

“However, our main interest with the Life Circuit devices is the feature wherein the subject might elect to increase negative resistance to a magnitude greater than the positive—i.e., apply a hyperloaded negative.”

No pun intended : calling a negative “hyper” loaded when the resistance has been increased as compared to the positive, is at the very least, a “loaded” descriptor.

Muscles contracting in a negative fashion are definitively “stronger” as compared to contractions in the positive.

If negative resistances that are increased relative to positive strength in a given repetition are to be called “hyper-loaded”, it logically follows that muscles contracting in a negative fashion are, *and should be called*, “hyper-strong”, independent of all other separate and independent variables.

The important point here — that as far as I can see is not yet mentioned in the recent dumpers articles — is that increasing the resistance in negative contractions, in and of itself, is NOT arbitrary.

The muscles contracting in this fashion ARE stronger.

While I realize this does not directly correlate … for all the trainers reading this … you are providing greater resistances for stronger clients … aren’t you?


avatar Joshua Trentine June 16, 2012 at 11:43 am

Hi Anthony,
This subject was actually covered already in a article called “Negative Thoughts” by General Tso. See if you can digest that article and get back to me with any specific contention to it. We have this stuff up so that we don’t have to continually answer the same questions.

Check out the article, it finally puts an end to the negative is stronger nonsense. Muscles produce contractile force with a signal from the nervous system, that force is identical whether the attached limb is moving up, down or holding still. Your ability to absorb forces is not more contractile effort. I’m sure this will become more obvious as you continue to train on that stuff.



avatar Craig June 19, 2012 at 12:25 am

I did take a look at that article. It doesn’t provide much substantive background information or any references regarding the evidence for or against the notion that muscles are stronger in negative extension versus positive contraction. You do mention some MedX results which you claim as flawed. And I do recall that you folks make a lot of references to some flawed work of A. Jones at Nautilus.

However, the observation that muscles are stronger at resisting extension than producing contraction seems to have originated with Adolf Frick in 1882. That was 40 years before Jones was born. There seems to be a whole body of evidence outside of the Nautilus/MedX literature that also seems to support the notion that muscles are able to resist stretching more powerfully than they produce contraction. Have you published your critique of this other evidence somewhere?


avatar Anthony June 19, 2012 at 3:37 am

Hey Josh

Thanks for pointing me to the articles, I’ll have a look.

— Anthony


avatar Scott Springston June 22, 2012 at 10:09 am

Tony, it’s good to hear you are having success with REN-EX. You are one of the few I have heard to say you are having a productive experience with their protocol. I have tried to use their protocol with my old Nautilus machines and it does give a good workout. It is undoubtedly a little safer than workouts where one is loosely swinging around barbells around but I didn’t find much difference in the safety or gains it provided over standard Nautilus protocol on the old machines I use. In fact I found I made better gains when I do several sets of an exercise vrs just one set and slightly faster reps and I do know how to push one set to the limit. I have no doubt that REN-EX works, I just don’t think it’s the holy grail REN-EX touts it to be. REN-EX just goes out of it’s way to act like it’s the only way one should workout and that just gets annoying. It’s just one of many ways to build muscle.


avatar Steven Turner June 17, 2012 at 8:58 pm

Hi Ken,

I am glad that you made the comments in your post – “before and after shots” as proof of evidence of someones results be it increase muscle or lose fat. If anyone wants to believe that “before and after shots” are proof of evidence of results, than if your bored and dumb enough watch all the inofomercial on TV in the middle of the night. My advice keep the debate at an intellectual level above the “before and after shots”.


avatar Drew Baye June 19, 2012 at 4:39 pm

I think that was the first time I’ve ever read the words “brilliant” and “bodybuilding” in the same sentence 🙂


avatar Joshua Trentine June 19, 2012 at 5:46 pm

ya…quite the oxymoron.


avatar joel waldman June 20, 2012 at 7:12 am

I thought the goal of strength training was to build strength, lean muscle mass, enhance flexibility, as quickly, efficiently as possible…within the constraints of safety….at some point if further strength gains are to be stimulated, exposure to heavy resistance seems to be a necessary stimulus…degrees of safety can be tailored to the individual…obviously different requirements for an osteoporotic fragile woman than an elite athlete…as long as normal precautions are taken…at least that’s what we try to do at Belmar fitness.


avatar JesseS June 20, 2012 at 2:04 pm


Appears to be opposite and completely unrelated to anything we’re doing.


His initial post/experience seems to be intimately related to the Dumpers series of articles you guys have written and are still writing.


avatar Joshua Trentine June 19, 2012 at 2:34 pm

Hey man, no offense intended, but if you don’t like all of our “talk” don’t read it.

We’re just out here trying to advance the field and we’re not concerned with your stamp of approval much less that of the brilliant bodybuilding community.


avatar Jonnie May 18, 2016 at 7:58 am

Abby, thanks for your sharing. I can relate to your feelings. What helps me is to think that even the closest person is weak, just like me. And I cannot be surprised if oclilaonascy that weakness pops up. However, I know that I can trust in God 100%. He will never fail me. So, if sometimes others are not meeting my expectations and maybe are letting me down, that’s Ok. I come to expect that, but I know that God will never fail!


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