Erection Rings, also known as Cock Rings, work by keeping blood inside the penis. Many men use these for a couple different reasons. One of the reasons is to keep a harder, more rigid erection. Another reason why men use erection rings is to last longer by controlling the urge to ejaculate. The third reason is to helping keep more blood in the penis for a much better sensation. Cock rings have been used by men for years with great success.