Dustless Technologies 13001 Filter Set for Wet-Dry Vacuum - Inner-Outer

These filters are sold in sets that include one outer filter and one inner filter for the patented Dustless Wet/Dry Vacuum.The Micro Prefilter captures dust particles down to 0.5 micron. That is amazingly close to what a HEPA rated filter captures at 0.3 micron. This is why the Micro Prefilter makes the Dustless Wet/Dry Vacuum so much better than other shop vacuums, and it is how the HEPA filter in Dustless HEPA Vacuums last so long. It is an incomparable asset. You can't fill the Micro Prefilter, by design. The vacuum holds up to 40 lbs of dirt and debris but the huge bag holds up to 80 lbs. That is so that at least 50 percent of the surface area is always available to support high airflow. The Micro Prefilter also retains its strength when wet.