Power Balance Viper Collection Hologram Wristbands Striking Colored Holograms Make a Statement! New Viper Collection wristbands are inspired by the fast lines and stripes of sports. Power Balance wristbands are crafted from 100% Surgical Grade Silicone. Durable and made to last, these new wristbands come complete with two Power Balance holograms in various colors. Power Balance Viper Collection Hologram Wristbands feature: Made with comfortable, durable 100% surgical grade silicone. Wristband is completely waterproof. Two holograms have cutting-edge, three-dimensional imaging. Hologram design is based on Eastern philosophies related to energy. Small (6.3") A* Medium (7.5") A* Large (8.1"). Size Guide: Find the proper size for your Power Balance wrist band in 2 easy steps. Power Balance...Prepare. Perform.