Feature: 1. Material: Made of healthy ABS and PC material, environmental protection, shockproof, anti scald, anti skid, explosion proof, reliable performance. 2. 3S Fast Heating: Simple to use, fast heating up in 3 seconds, double sided temperature heating warms your both hands. 3. 4000mAh Battery: Adopt 4000mAh capacity battery to give a full charge to most digital devices, The long lasting heat up to 4.5 hours. 4. Warm Gift: The hand warmers are suitable as a gift for family, friends and colleagues on any situations and festivals. 5. Portable: Handy carrying anywhere with any pocket or bag while sporting, fishing, hiking, camping, skiing, a perfect hand warmer solution in cold weather. Specification: Item Type: Double Sided Hand Warmer Material: ABS+PC Color: As Pictures Shown Weight: Approx. 189g/6.7oz Model: Battery Model L78 Input: DC 5V/2.1A Output: DC 5V/1A Power: 8W Charging Time: about 3.5H Use Time: 3-4.5H Product Battery: 4000mAh, 5V (Shipped with Built in Battery) Heating Method: Graphene Heating . Package List: 1 x Hand Warmer1 x Data Line1 x Manual 1 x Adapter1 x Lanyard1 x Storage Bag Note: Check the voltage of this product and the compatibility of this product before use.