Product Description Model High Middle Low Temperature of heater 60℃±5℃ 50℃±5℃ 40℃±5℃ Working time 120 minutes 160 minutes 220 minutes Material surface 100% Polyester inner 100% Polyester Far infrared heating,keep you warm in frigid high mountain and winter,perfect for outdoor activities under frosty climate. The heating element is distribed on back part which could relief the uncomfortable feeling resulted from coldness,speeding up blood circulation. Powered by high-capacity Li-on battery,three different temperature gear to be chose. - Far infrared heating - Keep you warm in frigid high mountain an winter - Perfect for outdoor activities under frosty climate - Battery has hign brightness LED light