Angle Flange Adapter For Nominal Duct Diameter 13 in Inlet Diameter 13 in Material Steel Product Type Angle Flange Adapter Material Thickness 20 ga Overall Length 5 in Maximum Pressure Rating 42 in wc Weight 7.02 lb For Duct Height 13 in Flange Inner Diameter 13 1/8 in For Duct Width 13 in Flange Outer Diameter 16 1/8 in Maximum Airflow 6 450 cfm Inside Diameter 13 in Number of Holes on Flange 8 Overall Width 16 1/8 in Bolt Circle Diameter 15 in Minimum Pressure Rating 2 in wc