Save maintenance and cleaning hassle – reusable filter frames coupling with patented, replaceable filter element, filter replacement can be carried out on site under 1 minute.  Dust and dirt are self-contained within the pleated filter element.  Collapsed filter element is just about 1/6 of a full size of bag filter.  Even government designated domestic garbage bags are sufficient to bag several filter elements once they were off from the AHU with least contamination to the premises.  Greatly eliminates airborne contaminants spread along the way to waste collection area.