The Nilfisk Nilfisk ALTO Aero 21 INOX is a powerful, easily-maneuverable yet heavy-duty shop vacuum. This popular wet/dry vacuum can be used indoors or outdoors and is ideal for construction sites, the automotive industry, body shops, and various other jobsites. A maximum CFM of 127, water lift of 84 inches, and stainless steel 5-gallon collection container make tough clean ups a breeze. It also features Nilfisk's Push & Clean system for semi-automatic filter cleaning.