Heart-2-Heart Cock Ring Elastomer Medium Blue. Elastomer is a polymer made up of carbon, hydrogen and oxygen. Known for its extreme elasticity, elastomer is the perfect material for cock rings. Because of its extreme elasticity, elastomer provides the maximum constriction of any product on the market. Elastomer returns back to its original shape as soon as it is removed and can be used over and over again. Compatible with all lubricants and 100% skin safe, elastomer is not only a great tight fit but a very versatile one too. Available in a wide variety of colors and in three sizes, elastomer cock rings are available in PHS International's H2H, M2M and Fresh product lines. The role of a cock ring is to provide constriction, this constriction slows the flow of blood from the erect penis creating an erection that not only lasts longer but is also thicker and harder.