Feature: 1. Heat Powered: No batteries required, the fireplace fan is powered by the heat produced by wood, coal or pellet burning stoves. Power and cost saving, reduce emissions due to fuel loss. 2. Quiet 4 Blades: The heat powered stove fan is in 4 blades design, all blades are well made, the spiral operation is quiet, and there is no big blower noise like other fans. 3. Automatic Working: When the surface temperature of the furnace body reaches about 122℉, it will start automatically. It does not need to be assembled and can be used directly. 4. High Speed: When the furnace temperature is low, the airflow is large and the operating speed of the fireplace fan is high. Speed can be up to 1400rpm. 5. Applications: This stove fan is suitable for people who do not want to use electric are and wish to improve furnace efficiency and use less fuel, and it is applicable to wood, gas and pellet furnaces. Specification: Item Type: Heat Powered Wood Stove Fan Specification: Butterfly (LT379) Material: Aluminum alloy Gross Weight: 602g / 21.2oz Size: Blades Fans: Total diameter: 152mm / 5.98in, height: 161mm / 6.34in Base: 88x54mm / 3.46x2.13in Color: Black Fan Blade: 4 blades Operating Temperature: 80 ℃ - 350 ℃ Air Volume: 180-220CFM Wind Speed: 1400rpm Noise: 25db. Package List: 1 x Wood Stove Fan1 x English Manual