1. Simple, the back of the hand is very hot. 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, ie the glove is light and can be cleaned.4. In a short time, it can reach a very comfortable and warm temperature of about 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 affect your productivity and ability to do your daily work and chores. Our handwarmer does not only give you a warm and comfortable cloth to warm your hands. It also heats up to fight and combat the extremely cold temperature, allowing you to function and prevent your hands from freezing.FEATURES:High-quality fabric and materialsWater-repellent and breathable fabric, powered by the lithium battery, warm & non-slipComes with heating and rechargeable feature.Battery material: polymer lithium battery (small volume, safe and explosion-proof)2 PCS 7.4V / 4000MAH lithium battery (single battery capacity 3.7V / 2000MAH, including batteries)Warming time: about 3 hours of constant temperature warmingSize: (approx.)M: width: 11.5 cm/4.53 in ; length: 28.5 cm/11.22 in; middle finger to the wrist: 18 cm/7.09 inL: width: 12 cm/4.72 in ; length: 29.5 cm/11.61 in; middle finger to the wrist: 18-21 cm/7.09-8.27 in