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 - 4.92 inches. Bottom Bead Width - 1.30 inches. Top Bead Width - .91 inches. One Year Manufacturer Warranty.