Intense Heat, Built for the Coldest Adventures Designed for those who challenge the outdoors. Whether you&&';;re hiking, skiing, or working in freezing temperatures, UT4 Extreme delivers unstoppable warmth and durability. Instant Heat-Up 3 Adjustable Heat Levels Each Battery Life - Lasts 6-16 hours per charge. IP56 Waterproof Protection Ocoopa is the only dedicated rechargeable handwarmer brand focused on complementing your lifestyle. With over 5 million users worldwide, we deliver the perfect palm of warmth to everyone. Weight: 1.54 lb (0.7 kg)