i found one that seemed ok from the reviews so i bought one. the odd thing i found about these is at just 5 mm the tube goes in fine. i pump it 4 or 5 times and feel it expand. i can only do a 10mm sound. i could feel the back of my penis and i could tell it was pretty large inside of me. i wanted to see how large it was inside of me so i started pulling with it still inflated. it started eazing out until it opend my slit and i thought would hurt like hell as it exited my open slit at 18 mm wide! how is it i can't take larger than 10 mm but the 18 mm exiting feels erotic as hell!