Portable & ConvenientHand warmer & flashlight 4-in-1 built-in 10000mAh lithium battery. Suitable for chilly office work, cold classroom, sleeping, shopping, walking dog, traveling, camping, hiking or any outdoor activities in the cold weather.easy to put it in your briefcase, in your pocket,palm-size, carry it in anywhere.DOUBLE SIDE HEATED & 3 DIFFERENT HEAT SETTINGS Press the switch and instantly release the warmth for you. Rapidly warm up all sides in seconds. 104/40; 122/50; 140/60. Use at low temperature for 104/40 12 hours,Constant temperature 122/50 8 hours, high temperature 140/60 10 hours,Please turn on the most comfortable temperature for youQuick heating hand warmerHigh capacity rechargeable battery, chargeful in 3 hours, and use at low temperature can for 8 hours,giving you long lasting warmth. Used as a power bank to full charge your electronic devices at any time, compatible with iPhone and android phoneEXQUISITE TO THE TOUCH Rechargeable Hand Warmers, with a high-tech aluminum and ABS material, thousands of polished exterior material, smooth and warm, portable and compact as well anti-skid in one hand.