1. Simple, the back of the hand is very warm. 5v voltage, safe and comfortable, promote blood.2. This product adopts high-tech heating material, adopts USB 5V low voltage, environmental protection and energy saving, safe and reliable.3. The product is soft and comfortable, and the activity is free. Simply open the inside of the glove and remove the internal heating element, that is, the glove is lightweight and can be cleaned.4. In a short time, it can reach a very comfortable and warm temperature of around 42 C.5. The style design is beautiful and suitable for winter use and gifts.6. Applicable scenes: cycling, sports trends, fitness equipment, running, outdoor travel. Freezing hands in winter affects your productivity and your ability to do your daily work and chores. Our hand warmer not only gives you a warm and comfortable cloth to warm your hands. It also heats up to combat and combat the extremely cold temperature, keeping you running and preventing your hands from freezing. FEATURES: High quality fabric and materials Water repellent and breathable fabric, powered by the lithium battery, warm and non-slip Comes with heating and rechargeable function. Battery material: polymer lithium battery (small volume, safe and explosion-proof) 2 PCS 7.4V/4000MAH lithium batteries (single battery capacity 3.7V/2000MAH, including batteries) Warming up time: about 3 hours constant temperature. warmingSize: (approx.)M: width: 11.5cm/4.53in; length: 28.5cm/11.22inch; middle finger to wrist: 18cm/7.09inW: width: 12cm/4.72in; length: 29.5cm/11.61inch; middle finger to wrist: 18-21?cm/7.09-8.27?in