Staminator Leather & Rubber Dual Cock Ring. Did you know that a cock ring may help increase your sexual stamina and performance? Made with quality Leather and rubber, the Staminator combines a leather cock ring and rubber shaft ring for twice the pleasure. Dual cock rings are characterized by one ring worn behind the testicles and one in front. Two rings are connected by a leather strap. Adjustable leather base ring and a 1.5 inches rubber shaft ring.