That's not an exercise machine, that's a spring-loaded genital noose. That is the wrong kind of well hung. In fact, you're being hung and drawn -- that's two-thirds of all the worst things even medieval psychopaths could do to the human body. Marsellus Wallace would approve. We should only be grateful the inventor didn't hear about quartering or he'd be advertising a pair of crossed blades to give you 400 percent more dick.
The patent claims to expand "without pain while holding a glans side of the penis," which is the most agonizing contradiction I've ever read. He states that the machine cannot be detached easily, as if that's a good thing, proving that he's been sent from a mirror universe to prevent regular Earthmen from breeding. The patent boasts that this can be used "even by a beginner for a long time with small pain," though describing their problem as a "small pain" is literally a dick thing to say to an amateur cock expander. The craziest bit? This isn't just a patent, it's a real product.
[NSFW] PeniStretcher by Wenck Medical Systems
You can actually hear it cackling.
Dick-stretching mail-order companies tend not to leave a huge academic impact, so I can't tell if the PeniStretcher (TM) from, I kid you not, Wenck Medical Systems uses the above patent or the other way around. I just hope neither is a rip-off, because that is the worst possible word to use around an extending metal dick harness.