These cock rings pack some serious zing Conductive silicone makes these bi-polar cock rings an exciting addition to any electro toolbox...Simply place the rings over your rod and connect them to your Zeus Powerbox (sold separately). Once the rings are on and hooked up, select your intensity level. A tantalizing current will flow from one ring and back, exciting the nerves along the way The silicone material is non-porous, allergy-safe, and easy to clean. Compatible with all Zeus Powerboxes and handheld systems, sold separately. Measurements: Small ring: 1.5 inches in diameter; Large ring: 1.9 inches in diameter. Material: Silicone. Color: Blue