elastrator
A tool that places a tight, elastic band around the neck of the scrotum. The band restricts almost all of the bloodflow to the testicles, resulting in a painful castration, also known as elastration, which takes anywhere between one hour or several hours to complete. It may occur in castration or castration play (the non-permanent counterpart).
Note: This should not be tagged on posts in which only elastration bands are shown.