Features [Good Versatility] With special reducing ring design, this check valve is suitable for most range hoods, suitable for pipe diameter of 80mm to 110mm. [Automatic Open and Close] Automatically open and exhaust smoke through the exhaust wind, and close quickly through gravity and strong spring. [Anti Odor and Mosquitoes] The check valve can firmly block outdoor odors and mosquitoes, keep your kitchen environment refreshing and clean. [Good Sealing] Using silicone sealing ring and backboard sealing strip, closely fit the range hood and wall, leaving no gaps and no smoke leakage. [Easy to Install] With upgrade design, the range hood check valve can be installed easily and quickly in simple steps. Specification: Item Type: Range Hood Check Valve Material: ABS Applicable Pipe Diameter: Approx. 80-110mm/3.1-4.3in Size: Approx. 17.5x17.5x12.5cm/6.9x6.9x4.9in Package List: 1 x Range Hood Check Valve 1 x Cable Tie 1 x Steel Rod Package List 1 x Range Hood Check Valve 1 x Cable Tie 1 x Steel Rod