<b>Why we need the stove fans? </b><br> 1. you will be warm throughout all your room!<br> 2. Save energy and cut your fuel bill.<br> How is KINDEN fireplace fan working without batteries or electricity？ <br> <br> It seems impossible, but this stove fan runs without batteries, cords or electricity.<br> <br> It works because heat is a form of energy. A bimetallic strip at the base of the fan converts a tiny fraction of the heat passing through it into motion.<br> <br> The fan spins when the temperature is reached 60°C(140°F).The hotter the base of the fan gets, the faster the fan turns, and the more air the fan circulates into the room.It will slow down and stop when the stove cools.<br> <br> The stove fan is designed for usage on freestanding stoves with a normal surface temperature of between 140ºF - 644ºF. Temperatures above this range may damage the fan and the electricity generating units. <br><br> <br> Material:Anodized aluminum<br> Air Flow: 380CFM (Max)<br> Running Speed: 1360RPM(Max)<br> Fan Height: 188mm/7.48inch<br> Fan Width: 182mm/7.16inch<br> Product Weight: 585g<br> Silent operation, the noise less than 25dB<br> Magnetic stove thermometer: Diameter: 6.5cm/2.6inch, monitor temp from 100-900°F(37.7-500°C)<br>