NORTECH Air-Powered Vacs are useful for dry pickup, vacs easily convert for wet pickup by removing the filter. Compressed air vacs develop up to 16" Hg (mercury) (8" Hg max. on 4-gallon vac). Order complete vacs or just the vac heads to attach to existing 30- or 55-gallon drums. All inlude exhaust filter and silencer. 15-, 30-, & 55-gal. vacs include internal filter, drum, dolly, 20' standard-duty hose, floor tool, crevice tool, 20' air hose. 4-gal. vac includes: 10'x1-1/4" hose, utility tool, ext. wand, crevice tool, and 12" of 3/8" inside dia. air hose and fittings. Made in USA.NOTE: 55-gal. vac consumes up to 2 gallons of material per second.NOTE: Vacuum Heads Only ship via small package carrier.NOTE Models 45296, 45524 and 45297 feature smaller orifices in air jet and venturi for lower consumption of compressed air.