Cock ring, also called penis ring, silicone ring, vibrating ring, etc. all works in a similar way: trap the blood inside the shaft of penis.
Function:
Cock rings enhance sexual sensation significantly for both men and women.
And improve the size and strength of erection.
How to use:
Fits it around the base of the penis, or the penis and the testicle, and applies pressure to the surround area.
This pressure squeeze the blood vessels that carry blood out of the penis and causes blood to leave more slowly.