Single, adjustable brush runs at 1800 RPM. Large 9 or 11 gallon solution tank and 7.5 gallon recovery tank. On-board power for optional scrub wand and extraction tools. The patented CFS (Chemical Free Solution) system requires Zero chemical or disinfectants. The CFS equipped machines use Ozone to sanitize, deodorize and purify soft floors using an innovative Ozone technology that's revolutionizing the way we clean carpets. Plus models have ECO plus solution tank. Momentary and continuous spray features. Single, adjustable brush. Dump hose built into unit for convenience. Not just clean, it's green. CRI Certified. Vac motor: 2 hp 3-stage; Brush motor: 1/6 hp.