Mount a Guardair Vacuum Generating Head on any standard 20 gallon drum* for instant, high-performance vacuum capability. Ideal for vacuuming up chips, dust, debris, liquids or sludge. Powered by compressed air, always dependable and trouble free with no motors or moving parts to wear out, Guardair Vacuum Generating Heads produce exceptional vacuum lift and vacuum flow while operating quietly and efficiently. Medium vacuum lift (S venturi) version available. Factory installed options include: Liquid Shutoff Assembly, HEPA Filtration, and Extra Silent Exhaust.*18 gauge minimum to prevent drum collapse. Non-returnable item.