The Macho Pulsating Erection Keeper Blue Ring. Super stretchy silicone vibrating cock ring. 7 variable functions. Vibrating ring provides for clitoral and testicular stimulation. Made using phthalate free, non-toxic materials: silicone. Battery included. Cock rings when worn around the base of the penis and testicles, many users find that cock rings increase sexual pleasure. Prolong rings, erection enhancement, climax control rings, cock rings. Always clean before and after use. The Macho Pulsating Erection Keeper Blue Ring from Nasstoys of New York. New image for 2013.