Features:1.Save Energy and MoneyThis stove fan runs without battery or electricity. Instead, it is powered by transforming heat into energy. There is a bimetallic strip at the bottom of the base which converts a fraction of the heat passing through it into motion. When the temperature reaches 60 centigrade, the fan starts to work. 2.Self-starting and Self-regulatingStart automatically when reached its min. temperature of 60 centigrade (needs half or one minute to preheat). Higher the temperature, faster it starts to spin. When the temperature exceeds 350 centigrade, please take your fan away from stove. The stove fan adjusts its speed with the stove temperature. The higher temperature, the blades spin faster, and the more hot air pumps into room. When the blades slow down, it means you should stoke the stove. room temperature can be increased by 41%, fuel costs up to 16%, no battery or power supply required, more environmentally friendly. 3.Whisper Quiet and No AssemblyThe blade design and no motor means the stove fan is nearly silent, able to use in a quiet room and unnoticeable against background noise such as TV. It is ready to use out of the box with no assembly. Read the user manual carefully before use. 4.Overheating ProtectionWhen the temperature reaches 350в„ѓ, the metal shrapnel at the bottom will lift the fan to protect the fan motor from damage. Features:Color: blackMaterials:main unit and blades: aluminum alloy; Air Flow:160-210CFMPower: Thermoelectric moduleOperating temperature range: 60 degrees в„ѓ to 350 degrees в„ѓ Package contents:1 × Heater Stove Fan