Add a little rhythm and shake to your sex life with this sensation-inducing PRETTY LOVE Heavy Balls Silicone Butt Plug. This weight will cause the balls to knock and shake, creating a unique sensation that once inserted will cause the wearer's muscles to contract and respond to the sensations. Waterproof. Material: Silicone. Dimensions: Overall Length - 3.34 inches. Width - 1.25 inches. One Year Manufacturer Warranty.