1. Specifications: - Product type: Range hood check valve - Material: ABS - Applicable pipe diameter: Approximately 80 - 110 mm / 3.1 - 4.3 inches - Dimensions: Approximately 17.5 x 17.5 x 12.5 cm / 6.9 x 6.9 x 4.9 inches 2. Features: - This check valve with a special reducing ring design is suitable for most range hoods and pipes with a diameter of 80 mm to 110 mm. - It automatically opens through exhaust air to expel smoke and closes quickly due to gravity and a strong spring. - The check valve can firmly block outdoor odors and mosquitoes, keeping your kitchen environment fresh and clean. - Using a silicone seal ring and a back - panel sealing strip, it tightly fixes the range hood to the wall without any gaps or smoke leakage. - Due to the improved design, the range hood check valve can be easily and quickly installed with simple steps. 3. Package list: - 1 x Check valve - 1 x Cable tie - 1 x Steel rod