Coway-USA HEPA Filter for Model AP-0510IH 3 Year Replacement Filters - Included is 2 HEPA filters (need 2 per unit)for AP-0510IH HEPA Filtration - Designed to capture 99.97% of airborne allergens as small as .03 microns in size. Pathogen Eliminator - HEPA filter?s - 99.97% clarity will effectively rid the air of dust, smoke, pollen, mold and pet dander.