"Some men are confused (or rather not as educated on the matter) and they believe that the outside skin get’s longer and thicker. That’s false. However, some men have false expectations; they think using a penis pump once will cause them to have a bigger penis permanently, and that’s false. As in the gym example before, you have to keep at it, and you have to practice to see results. Yes, early on you will see results like any newbie in the gym, but if you don’t keep at it you will see those results diminish,” says Dubois.
Devices that wrap around the penis, placing a squeezing type of pressure, are advertised as methods of stretching it out. Some are suggested for use during an erection, and some for when you are not. The rationale behind these devices is based on the idea that forcing the skin and structures of the penis to narrow could allow it to lengthen. A specific device is also marketed for use during jelqing. There is no evidence that wrapping anything around your penis will lengthen it, and these devices can cut off blood supply, causing permanent damage.