The 17.72 in. x 17.72 in. Square Aluminum Automatic Gravity Shutter Louver Vent, perfect for homes, garages, and greenhouses. this durable shutter is made from high-quality aluminum, ensuring resistance to corrosion and rust. Its precision-engineered louvers fully close to prevent water intrusion, making it suitable for harsh weather conditions. The automatic opening and gravity-closing mechanism allows for effortless operation, working seamlessly with an motor and fan blade to cool your space and remove excess heat, moisture, and dust. (Note: exhaust fan blade and motor sold separately.) Upgrade your ventilation system with the reliable Automatic Gravity Shutter for a more comfortable environment. Color: Silver.