American Aldes 99 028 Spring Loaded Backdraft Damper

Spring Loaded Backdraft Damper with high quality EDPM internal rubber gasket and exterior foam gasket to prevent undesired reverse airflow.and air leakage in intermittent exhaust or supply systems. These units are sized to be installed in 4 Inch through 8 Inch and 10 inch through 16 duct isntallations and feature the following: • 20 gauge galvanized steel housing • Aluminum spring loaded butterfly damper blades • Damper seals against EDPM rubber gasket in closed position for minimal leakage • Gasket designed for use in temperatures from - 22°F to180°F • Require from 0.04 to 0.08 inches W.G. to begin to open • May be installed in any position. (14" and 16" models require adjusting spring tension if used in vertical position, with airflow down) • Simple installation - entire assembly inserts into duct • Exterior foam gaskets assure a tight seal against interior surface of duct