1. rapid heating and constant temperature to keep warm: 5 seconds rapid heating to a comfortable temperature of 55, intelligent constant temperature to prevent overheating, continuous heating, outdoor hands are not frozen in winter.It can be used repeatedly every year. 2. Portable, compact and easy to carry: the palm size is lightweight, and it can be put in a pocket/backpack to warm hands anytime, anywhere when commuting, shopping and traveling. 3. Safety and explosion-proof multiple protection: explosion-proof battery core+flame-retardant shell, triple protection of overcharge/overtemperature/short circuit, and double safety and no hidden danger in charging. 4. The skin-friendly material is comfortable and durable: the skin-friendly suede material is soft to the touch, anti-slip and sweat-proof, resistant to slipping, wear and fall, and not easy to deform and damage after long-term use. 5. Outdoor travelers: takeaways, couriers, riders, mountain climbers, commuters, frostbite prevent