Check the listing for details. 4" Duct Connector Flange for Heating Cooling System, Galvanize Steel. Condition: New. Listed at 23.55 USD. Duct flanges are widely used for air ventilation systems in homes, kitchens, bathrooms, garages, factories, etc. What's more, it can be used on welded exhaust pipe, spiral exhaust pipe, exhaust pipe elbow fittings, fan hose connector.SpecificationColor: Silver ToneMaterial: Galvanize SteelInterface Dimensions: 106 x 103 mm / 4.2 x 4.1 inch (OD*ID)Overall Height: 20 mm / 0.79 inchThickness: 1.5mm / 0.06 inchBase Outer Diameter: 163mm / 6.42 inchScrew Hole Diameter: 10mm / 0.4 inchPacking List: 1pcs x Duct Connector, 1pcs x Aluminum Foil Tape, 50mm in Width and 10 Meters in LengthAdvantages1. The flange is made of galvanized steel, which is wear-resistant, strong in corrosion resistance, not easy to deform, and durable.2.