Duct Collar w/Damper For Nominal Duct Diameter 4 in Material Steel Overall Length 5 in Material Thickness 26 ga Weight 0.8 lb Maximum Pressure Rating 3 in wc For Duct Height 6 in Shape Round End Type Crimped For Duct Width 4 in Gas Appliance Category Not Applicable Inlet Diameter 4 in Damper Type Low Leakage Inside Diameter 4 in Flange Outside Diameter 1 in Outside Diameter 4 in Flange Inside Diameter 4 in Color Silver Outlet Diameter 4 in Overall Height 6 in