Features: brand new and high quality Eco-Friendly and Self-Powered: Thermoelectric module acts as a small generator to power the fan's motor. No batteries or electricity required! Improved warm air circulation results in greater comfort and reduce wood consumption from your stove. Longer Lifetime: There is a Bi-metal safety device in the base of the fan.If the surface temperature rises above around 300°C, the safety device gently elevates the front of the fan to protect the TEG and motor. Save Energy: Efficiently drive warm air throughout the room. Less consumption, more efficiency. Start Automatically: Upgrade technology, faster speed, larger air volume.The heat powered stove fan is designed to circulate the warm air created by a wood, coal or pellet burning. Efficiently circulates warm air throughout the house. Whisper Quiet: Newly Designed Blade,Larger Air Volume,Lower noise.You don'for t even know the stove fan is there,but you feel the warmth!You will enjoy the warm air in a quiet and comfortable environment. Specifications: Material: Aluminum Alloy Color: Black, Silver Product Dimension: approx. 180x110x130x105x80 mm/ 7.09x4.33x5.12x4.13x3.15 inches Net Weight: 980g/ 2.16 lbs Package Includes: 1PC 4 Blades Heat Powered Stove Fan note: Please allow 1-2cm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Fixed Collar Use Note: The coil is suitable for chimneys 5-6 inches in diameter. 1. Use a screwdriver to turn the nut left and right to control the size. 2. Adjust to the right size and fix the fan.