Zolo Extra Thick Silicone Cock Rings 3 Pack from X-Gen Products. For a firm grip that will enhance your size and girth, this set offers three thick, soft, stretchy silicone cock rings in various sizes. Find your perfect fit or combine the rings for cock and ball play. Ultra tough, stretchy silicone design. Extra thick set of 3 cock rings: 1.25 inches, 1.5 inches, 1.65 inches.