The shutter louvered vent is designed to open and close automatically using gravity, normally used with flow fan for air exhaust and ventilation. It has good ventilation performance and easily block backdraft and unwanted air, moisture and dust. Specification Color: White Material: Aluminum Alloy Interface Diameter: 300 x 300 mm / 12 x 12 inch(L x W), suitable for 12 x 12 inch vent hole and duct opening Packing Listing: 1 x Exhaust Fan Louvered Vent Advantage The Louvered Vent is constructed from top-grade aluminum, ensuring long-lasting durability with resistance to corrosion or rusting. Instruction 1. Remove the protective grille of the flow fan; 2. Embedded the vent cover into the fan outlet; 3. Fix the vent cover with screws(not included) NOTE Before the installation, ensure that the vent cover dimensions match your flow fan or wall openings.