I have had a Penistretcher for 2-1/2 years and have figured out how to use it.
First, use gauze or other material to wrap your penis where the noose goes around. This pads it and absorbs perspiration. Otherwise, the noose sticks and causes lesions that take about a week to heal. A gauze pad wrapped around the base over the pubis helps comfort, too.
Second, you need to put the device on an electronic scale, zero the scale, and then push down to measure the force, marking at 900 g, 1200 g, and 1500 g. with the edge of a file or something. Otherwise, you can’t tell what force you are exerting. Start at 900 g and work up. You should be able to wear the device for about 1-1/2 hour at a time before it gets painful. If you can wear it longer, it is not stretching enough. After taking the stretcher off, you should work the blood back into the penis until it feels normal. You can then either wait a few hours to put the stretcher on, or put it on immediately, although I would suggest at a lesser force if immediate, as the object is to maintain the stretched length, not to cause damage — it it hurts, quit for a while. The initial stretching can stretch ones penis 50mm, which will shrink back over several hours, so maintaining the stretch is enough. I have grown from 4-3/4" (12cm) to 5-3/4" (14.7cm) and my girth increased from 4-3/8 (11.2cm) to 4-5/8" (11.8cm) over the 2-1/2 years with a couple of months off from time to time, mostly wearing the stretcher 1-1/2 hours three times per day. I would have done much better had I know what I write here earlier. Your mileage may vary.
I have used the Penistretcher and similar devices off and on for 2-1/2 years. I have also purchased a Penimaster https://www.a-mans-world.com ), which has an inferior head device but the best engineered shaft with gradations which allow much better calibration of the tension; it maxes out at 1200 g. The Andro Medical Andro-Penis (Men’s Health devices - Penis, ED, Peyronie or https://www.fastsize.com ) is not as well engineered, but has calibrations and will go to over 2000 g, but is less precise below 1200 g. I have put the Penistretcher head on the Penimaster shafts and had great success. The AndroPenis is only for very advanced stretching.
I have also recently taken up Jelqing. It took a while to figure that one out, too. Basically, do you remember when you were young and beat your meat too hard and too long and it would swell up? Well, that is what you are doing with jelqing. After beating your meat, concentrating pressure on the sides where the spongy tissue is, you can squeeze the penis base and head and balloon the penis shaft, holding it a while to pressure the tissue. The first month, before I figured this out, nothing happened, as advised by the jelq sites. Since then over two months I have enlarged the diameter from 4-5/8" ((11.8cm) to 5-1/8" (13cm), my goal. I have also been ballooning the penis head; I don’t know if that has helped, but I have maintained good proportionate size.
Good luck