Duct flanges are widely used for air ventilation systems in home, kitchen, bathroom, garage and factory etc.SpecificationColor: GreyMaterial: Galvanized IronInterface Outer Diameter: 295 mm / 11.6 inchDiagonal Mounting Hole Distance: 316.5 mm / 12.5 inchDistance Between Adjacent Mounting Holes: 158 mm / 6.2 inchBase Outer Diameter: 327 mm / 12.9 inchPacking List: 1 x Duct ConnectorAdvantages1. The connector is made of galvanized iron, which is anti-corrosion, cold-resistant, high-temperature resistant, not easily deformed, and durable.2. The base of the connector has screw mounting holes, no drilling is required, and it is directly fixed on the wall with screws, which is easy to use.3. The surface of the ventilation flange is smooth, which is conducive to connecting the air duct.