Features: Intelligent temperature control, heated with knees, back and waist. Powered by any 5V / 2A USB portable charger, the USB plug is compatible with most portable chargers on the market. Which can start heating in 30 seconds, long duration and long heating time. 3-level adjustable temperature with indicator light to adjust the required temperature. Safety insulation design, built-in thermal protection module, 5V safety voltage, once overheated, it will stop running until the heat returns to the standard temperature. Support manual/machine washing.The safety protection function ensures that the machine is not damaged during washing. Heating underwear helps to improve blood circulation, enhance metabolism, which is very suitable for people who are afraid of cold, Raynaud's disease, arthritis, poor blood circulation, and stiff joints. The best solution for various outdoor activities, such as skiing, fishing, jogging, Hunting, biking, hiking motorcycles, protecting climbing dogs, Running, snow removal, etc. Specifications: Name: Heated Thermal Underwear Color: Black Gender: Men Material: 95% Cotton + 5% Spandex, Carbon fiber wire Heating temperature: Red LED 50℃, Bule LED 40℃, Green LED 30℃ Power supply: USB power bank (not include, 10000mah power bank can be heated for about 6-7 hours) Size: M, L, XL, 2XL Season: Autumn, winter Package includes: 1 x Heated Thermal Underwear Tops 1 x Heated Thermal Underwear Pants (Note: Not included power bank)