I'll do about 3 -10 minute sessions in 45 minutes. I increase the pressure after a few minutes after my cock gets used to lower pressures. I do get the pressure pretty high at times, just don't go too far. my easy rule, don't do it if it hurts. I am trying to use a pump to gain length. I have a 2in by 10in cylinder, and my girth totally fills it, so I am really pulling my cock up the tube. I have been stuck on 7.25 length for years, tonite I almost got to eight inches with the pump. what it will do on its own, will have to see. hope this works, if it doesn't i'll settle for what has happened, my head has got bigger, broader, and my cock is a uniform thickness top to bottom.