I've used this thing on and off for a few years. I have found that 1 hour sessions 3-4 days in a row produce the best gains in size. I have not really noticed any significant length gains but for thickness the thing is incredible. I can double the thickness of my cock with it. The full effect lasts only about 1-2 hours but I would say 40% of the thickness gains last for a few days. Used with a cock ring (for after you take it out of the cylinder) and Viagra you can really take your cock size to another dimension and do some serious log jammin.