Duct Reducer For Nominal Duct Diameter 17 in 18 in Inlet Diameter 18 in Inside Diameter 18 in Overall Length 7 in Product Type Reducer Weight 21 lb Material Thickness 20 ga Maximum Pressure Rating 42 in wc Maximum Temperature Rating 390 Degrees F Material Steel Seal Material Nitrile Standards Not Applicable Shape Round Gas Appliance Category Not Applicable Maximum Airflow 12 370 cfm Outlet Diameter 17 in Overall Height 11 in Overall Width 18 in End Type Quick-Fit