describe:   *1. Housing material: plastic   *2. Dimensions: 110 x 60 x 40 mm   *3. Power supply: USB charging   *4. Rated voltage: 2A   *5. Rated power: 5V   *6. Battery capacity: 5200mAh   *7. Calories: 3 settings   feature:   *1. 3 levels of temperature control, double-sided heating, you can choose the best temperature according to your needs, and keep your hands warm even on cold days.   *2. USB charging is fast and convenient. When the power is exhausted, just plug in the USB data cable to charge the 2400mAh battery, and the heating element adopts ceramic heat dissipation technology, and the heat preservation time can reach about 5 hours.   *3. It can be carried with one hand or placed in your pocket. It can be used to warm your hands, feet, knees, and belly. You can take it with you when you are exercising, fishing, hiking, camping, skiing, traveling or outdoor sports.   *4. No need to add water, safety explosion-proof, automatic power-off protection, intelligent temperature control system to prevent overheating.   *5. It is the perfect gift for family and friends to spend the cold winter.   The package includes:   1 *Hand warmer