For welding extraction, on-torch or nozzles. Semiportable installations. Unit including Nederman FlexFilter cyclone for coarse separation. Manual start/stop. The units have four 100mm diam. (C-PAK 20-1500)/160mm diam. (C-PAK 20-2500) vacuum inlets with connection flanges suitable for the Nederman PAK hose and coupler system. Flow restrictor and combined back flush/start-up valve is standard.