Nilfisk Aero 21, 5 Gallon Wet Dry Vac | Nilfisk HEPA Vacuum | Powerful & Versatile Cleaning SolutionAERO 21 is the smallest model in the AERO series with compact design and easy to use features such as Push&Clean filter cleaning system and convenient accessory storage. The 20 liter machine has efficient suction performance and is found with optional INOX stainless steel container with robust trolley and lifting handle. Power socket with AutoOnOff is found on ( 21) models, which activates the machine by the connected drilling, sanding or cutting