Rub-a-dub-dub, let's play in the tub! The Waterproof Mini-Mite massager requires just one AA size battery which is not included. The mini massager is just under 4 inches long, so it is perfect for discreet travel. The silicone sleeve will fit right over the entire massager unit which comes with 5 different massaging heads. Perfect for the tub, beach or pool!