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