Sir Richard's Control Silicone Super Nut C Ring Black from Pipedream Products. Control offers measured restriction for harder, stronger, longer erections and intense orgasms. Creating the world’s most comfortable cock ring demanded the best material available, extremely stretchy silicone with a non-pinching surface, providing even pressure and greater results. Reversible, wear on shaft or testicles.100% Silicone. Body safe, hypoallergenic, phthalate free.