The patented Wet Dry Dustless Vac is the only vacuum that allows you to go from wet to dry without switching filters. A baffle inside the barrel keeps the water away from the filters, and a check ball prevents overfilling, making the Wet Dry Dustless Vac unlike any other vacuum on the market today. The patented filtration system of the Wet Dry Dustless Vac allows you to clean the filters without opening the barrel for a more dust-free work environment. An excellent choice for contractors and DIY homeowners who do not need to meet EPA or OSHA guidelines but want effective and economical dust control, this vacuum provides almost HEPA performance. The disposable and tear-resistant WunderBag micro pre-filter captures particles down to .5 microns, amazingly close to HEPA filters that capture down to .3 microns. Best for capturing fine dust from drywall sanding, grinding/cutting of concrete, brick, stone or fibreglass.