Nilfisk ALTO Aero 21-01 5-Gallon Wet/Dry Vacuum - HEPA (900140) It features a 127 maximum CFM and 84-inch maximum waterlift Push & Clean system features semi-automatic filter cleaning for quick and easy maintenance. HEPA filtration removes up to 99.97% of airborne particles down to .3 microns. A standard outlet powers this model for indoor or outdoor wet/dry clean-up. An extra-long hose, extension tube, and various other tools make cleaning more convenient.