Replacement filter is designed for Fellowes AeraMax 290 Air Purifiers The True HEPA Filter captures 9997 percent of airborne particles as small as 03 microns, including pollen, ragweed and other allergens, viruses, germs, dust mites, mold spores and odors AeraSafe antimicrobial treatment provides builtin protection from the growth of odorcausing bacteria, mildew and fungi on the True HEPA filter The filter should be changed once a year