Nilfisk ALTO's newest line of wet/dry vacuums—the AERO series—are engineered for long-lasting indoor and outdoor wet/dry applications. The Nilfisk AERO 21 is the most compact in the series and is great for customers who need a reliable, powerful yet maneuverable vacuum at an affordable price. Ideal for cleaning residential spaces, workshops, or small- to medium-sized job sites, this 20-liter model is easily transportable and comes with integrated accessories. This HEPA-certified model catches even the smallest particles (99.97% of particles down to .3 microns). It complies with EPA RRP, OSHA, NIOSH, and DoD standards.