Pimiho hand warmer is easy to use, runs hot enough to keep your hands warm on a cold day outdoors, offers a bit under seven hours of battery life at its highest temperature setting. It doubles as a backup battery for your mobile phone, It is a nice size to hold and feels smooth in your hands.You can keeping it in a pocket. Why Choose Pimiho Hand Warmer: Double-side heat: Similar hand warmer in the market can just heat at one side, while this product will heat in both sides, more cozy to use. Size ideal match hand shape, you can just hold it in the hand to get the cozy warmth in the cold winter.||Intelligent temperature control: It will automatically sleep in non-working state to prevent power loss. Energy saving. 3 temperature levels: 3 temperature available for choose, you can choose as per your needs. 2 IN 1 design: It can use as a power bank, or a hand warmer, very practical for use.||Equipped with protection board to prevent overcharge, over discharge,short circuit effectively; can automatically detect and adjust the charge and discharge voltage and current, truly protect your safety. Power output using USB port, plug in the data cable to achieve portable, charging and use at any time, any occasion. Specifications: Ring lights green: 100-105°F (38-40°C)-low temperature Ring lights orange: 106-111°F(41-43°C)-medium temperature Ring lights red: 112-118°F(44-48°C)-high temperature Battery capacity: 5,200 mAh Micro USB Input: 5V/2A USB-A Output: 5V/2.1A (Max 2.4A) Size: 105*50*30mm Weight: 155g Battery capacity: 7,800 mAh