120 Cooling Holes: There are 16 cooling holes on the side of the hand warmer and 4 cooling holes on the top. 2Fashion Design: Made of zinc alloy material, strong and durable, with highly polished finishes and stylish design. 3Insulation and Heating: After ignition, cover the lid and put the hand warmer into the insulation bag to prevent overheating. Soft insulation bag can maximize heat preservation. 4High Heat Dissipation: Using physical principles to ignite and heat, it can provide up to 12 hours of soothing warmth, and can provide constant temperature heat dissipation for long time. 5Applicable People: Easy to carry, the reusable hand warmer is suitable for the elderly, pregnant women and children. It is a good warming product for office workers.