with guards, it will automatically shut off after 25 minutes of heating time to prevent working too long or overheating. This portable hand warmer has an aluminum casing with a smooth surface and a comfortable touch. Double-Sided Quick Heating 2-Level Heat Setting : Press the button to switch to the warm mode, then immediately release the heat from the double-sided in 3 seconds, the double-sided heating helps to warm your hands. Then there are 2 temperature settings (113-122F/ 131-140F), you can adjust the temperature according to your needs. Portable Hand Warmer : The mini hand warmer is small in size, easy to carry, and easier to put in the pocket, perfect for men or women in cold winter. The hand warmer can last up to 12 hours to ensure long-term use and is suitable for a lot of winter outdoor sports.It can also become a power bank Relax your body : This hand warmer can relax your body by vibration (please switch to the warm mode first, then press and hold for 3s). This hand warmer is suitable for the neck, arms, legs, calves, thighs, shoulders, back, waist and feet. And while relaxing the body, it can continue to heat to keep you warm, making you feel more comfortable in the cold winter, very suitable for mountaineering, hiking, traveling, camping, skiing, cycling, etc. Best Gift Quality After Sales : This hand warmer is the best gift for kids, youth, boys, girls, men, women, elderly. If you encounter any problems during the use of the hand warmer, please feel free to contact us, and we will reply to you within 24 hours. Specifications: Material: ABS Heating mode: USB Rated power: 5W Output voltage: 5V-1A Endurance market: 3-6 hours Power failure protection: Yes Heating time: 3S Second gear temperature regulation: 50-55 Package list: Hand Warmers*1 User Manual*1 Charging table*1