Flange Adapter For Nominal Duct Diameter 4 in Inlet Diameter 4 1/2 in Material PVC Product Type Angle Flange Adapter Material Thickness 0.3 in Overall Length 8 1/2 in Maximum Pressure Rating 10 in wc Weight 1.25 lb Flange Inner Diameter 4 1/8 in Flange Outer Diameter 8 1/2 in Inside Diameter 4 1/2 in Number of Holes on Flange 4 Overall Width 8 1/2 in Bolt Circle Diameter 6 3/4 in Minimum Pressure Rating Not Applicable Shape Straight Outlet Diameter 8 1/2 in