Come and see our amazing products. The professional hand warmer adopts advance heating flims, press the switch and instantly release the warmth for you rapidly warm up double sides in seconds. 3 levels of temperatures adjustment: 95-107degree F/104-118degree F/118-131degree F, you can choose suitable temperature according to your own demands. PLEASE fully charge the batteries before using it for the first time. The electric hand warmers are equipped with Tesla same power battery 5V, 9000MAH lithium polymer batteries., providing up to 14 hours of battery life. The battery has indicator to show battery percentage, so you don't have to worry about power outages. Pls confirm further with us if any query about packing info, inventory status and time schedule.