Machine Adapter For Nominal Duct Diameter 13 in Inlet Diameter 13 in Material Stainless Steel Product Type Machine Adapter Material Thickness 20 ga Overall Length 5 1/2 in Maximum Pressure Rating 42 in wc Weight 2.45 lb For Duct Height 13 in Flange Inner Diameter Not Applicable For Duct Width 13 in Flange Outer Diameter Not Applicable Maximum Airflow 6 450 cfm Inside Diameter 12 7/8 in Number of Holes on Flange Not Applicable Overall Width 13 in