Product Name: Hand Warmer Material: Aviation Aluminum + ABS Color: gold, silver Shape: Cobblestone Heating method: electric heating Input voltage: DC5V-2A Output voltage: DC5V-2A Working hours: 4-8 hours Battery capacity: 5200 mAh Battery type: polymer lithium explosion-proof battery Features: *1.double-sided heating, you can choose the best temperature according to your needs, even in the cold days can also make your hands stay warm. *2. USB charging is fast and convenient, when the power runs out, just plug in the USB cable to recharge the 5200mAh battery, also, the heating body using ceramic heat dissipation technology, heat retention time can last about 5 hours. *3. 2-in-1 hand warmer, can also be used as a power bank to charge your cell phone, can be carried in one hand, or in a pocket, can be used to warm hands, feet, knees, belly. You can carry it with you during sports, fishing, hiking, camping, skiing, traveling or outdoor sports. *4. No need to fill water, safe and explosion-proof, automatic power-off protection, intelligent temperature control system to prevent overheat. *5. It is the perfect gift for family and friends to spend a cold winter. Notes: 1. Manual measuring, please allow 1 ~ 3mm error,thank you. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. We guarantee the style is the same as shown in the picture