yesterday i used the 20 mm peridise first and then the 16 mm in the order of bigger to smaller that so many posts have praised–it was nice and i think that bigger to smaller makes more sense than smaller to bigger( which i have also tried many times)–had a good time but no advancement from earlier sessions–took the next day off as i have been going daily and even several times daily for last week or so and maybe my prostate needs a day without stimulation for some recuperation–i will just do my rubbing exercises and leave it at that–they really get the blood flowing and awaken the prostate without getting it taxed too much like the peridise does–couldn't get the "ball popping" type of orgasm going–had only the rubbing and some "ball popping" , but none continuous like i've been able to do before with contractions