I use a penis stretcher over a year
and a half. During this time I found that I get different results in plus and minus. After a while I`be notice that I do not measure in the way. Below I will try to explain how to build a simple measuring device that will give you always the same results.
All you need is two tubes. One (external)tube should be big enough to place your penis in. Second tube (internal) should have closed one end and a measuring scale on the outside surface. You put your penis into the bigger tube and than place a smaller one into. You read a value on the scale. I will try to put a simple sketch if someone ingested in.