The 4307 Challenger Series tri-lobe blower package from National Vacuum Equipment includes a 535 cfm blower that can generate 26 to 27 inches Hg of continuous vacuum power, depending on working conditions. It has stainless steel intake and ballast air silencers, 3/8-inch steel mounting brackets protected by powder-coated paint, factory-connected elbows, fittings and high-temperature hoses and a diesel flush kit. It can be powered by either gearbox, hydraulic or belt drive configurations. A ballast air cooling system, which injects cooler ambient air into the exhaust side, keeps the blower from overheating while maintaining full vacuum power. 800/253-5500; www.natvac.com.