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 - 4.05 inches. Bottom Bead Width - 1.02 inches.  Top Bead Width - .87 inches. One Year Manufacturer Warranty.