Dust Collector Hose Fittings. 863 results. Results. Overall Pick. POWERTEC 70322 4 Inch to 2-1/2 Inch Reducer and 4 Inch Dust Control Flex Cuff with Stainless Steel Hose Clamps, Dust Collection Fitting for Woodworking Dust Collection Hose and Dust Ports, 1 Set. 468. 400+ bought in past month. $1269.