Duct Collar w/Damper For Nominal Duct Diameter 12 in Material Steel Overall Length 5 in Material Thickness 24 ga Weight 2.9 lb Maximum Pressure Rating 3 in wc For Duct Height 6 in Shape Round End Type Crimped For Duct Width 12 in Gas Appliance Category Not Applicable Inlet Diameter 12 in Damper Type Low Leakage Inside Diameter 12 in Flange Outside Diameter 1 in Outside Diameter 12 in Flange Inside Diameter 12 in Color Silver Outlet Diameter 12 in Overall Height 6 in