Vin Vac is much stronger than
xtreme models but it can be unsafe as it not a built in feature of the device. I used
x40 with vin vac 3 x 5 mins causing pain to my dick but bearable my base of my dick was 7" and rest of shaft was over 6."1/2" on my dick in 15 mins.This is inadvisable as i had a lot of fluid build up it was so blown up i couldn't retract my foreskin(which is sort of tight anyways). We all have the tendency to do too much PE.So start slow and build it up.