We found these unique devices and thought that they might be handy holding the folks with foreskin back while estimming, especially while using urethral inserts. You might find other uses for these rings, even if you don't have foreskin.  Just let your imagination kick in. 

Soft silicone, easy to clean, re-usable, pliable and comfortable to wear.  

Produce Dimensions: ThreeStyles are Included

One Inch Equals 25.4mm