SmartBalls might look unusual, but they can make an unbelievable difference in your sex life. These silicone-coated balls contain a smaller set of balls that rotate silently, generating incredible vaginal sensations. Muscles of the pelvic floor are stimulated, massaged and "exercised" providing a targeted workout yielding greater sensations and control during lovemaking. Detailed operating instructions are included and a sample of our lubricant Bodyfluid. Waterproof. (4 in.)