Cock rings are erection enhancing male sex toys that help maintain a stronger erection by preventing blood from flowing out of the penis once erect. Cock rings are made out of many different types of materials including stretchy jelly, silicone, rubber and leather. To use, you slip a cock ring over the semi-flaccid penis and continue stimulation until fully erect. There a several types of cock rings; a simple ring that can be used around the base of the penis or behind the testicles, a more advanced model that has two rings, one that sits at the base of penis and another that goes around the testicles, and vibrating cock rings that have small bullet vibrators attached to them that can be used for clit or testicular stimulation.