The 94311 HVAC ventilation duct cleaning solution was developed to address the many commercial properties which have the new open ceilings with exposed mechanical ducts. Round ventilation duct is also present in many establishments and homes where the rustic industrial look of exposed duct work is considered aesthetically attractive. The system is designed to be used with standard commercial back pack vacuums, commercial vacuums with 1.50 in. hoses and home shop style vacuums again with 1.50 in. hose. The wand fits male into industry standard 1. 50 in. cuffs and features a 45° bend which helps facilitate cleaning of large diameter duct. The 3 brushes feature a 90° pivoting connector which locks to the wand permits the tool to pivot as it tracks the surface of the duct. Extensive testing lead to the double brush configuration to assure the dust is captured not simply brushed from the surface. Contact cleaning is preferred and necessary to insure capture of the particulate on the rough surface of most HVAC ventilation duct. The 94311 is compatible with all major brands of commercial vacuums equipped with 1. 50 in. cleaning accessories including Pro-Team, NSS, Tennant, Powr-Flite, Mosquito, Perfect, Hawk, Bissell, Hoover, Mercury and Sandia. It is also compatible with canister vacuums produced by these same companies as well as common home shop style vacuums with 1.50 in. hose like Shop Vac, Rigid, Vacmaster, Workshop and Craftsman.