Environmentally friendly Powered by heat, no batteries or electricity. Taking full advantage of the heat of the stove, fireplace fan is designed to spread heat throughout the room. Circulate the heat sensibly, no need to move to the fireplace, no more bothered by the cold! Automatic and Quiet Operation -- When the temperature of the fireplace reaches 40C, the fan will automatically start spinning. 80-345C is the normal operating temperature. The higher the temperature, the faster the fan spins and the heat propagation capacity is stronger! It is worth noting that the whole process is quiet (less than 25dB), even if you are resting next to it, without any influence! HighEfficiency A large-area sawtooth heat sink helps dissipate heat more efficiently. When the temperature reaches about 40C ...