Feel the excitement of penetration again and again with this self penetrating butt plug! A new and unique concept will take anal pleasure to a whole new level! The secret of this exhilarating butt plug lies inside its very smart construction. A hidden tube contains 2 heavy balls that will shift up and down during your movement(s) causing extra anal stimulation like you're getting penetrated over and over again! This Black Beauty is totally waterproof and made of smooth, phthalate free medical-grade silicone. It stands 12.7cm (5inch) tall and has a maximum girth of 3.6cm (1.42inch) with a top measuring 5.65cm (2.23inch) in diameter.