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