Friedrich AP260HFRK Annual HEPA Filter Replacement Kit for AP260 High Performance HEPA Filter removes 99.97% of all particles greater than 0.3 microns from the air Effectively filters out smaller particles such as dust, pollen, mold spores, and allergens Contains 2 Antibacterial/Antifungal Multi-filters (replace every 6 months) and 1 High Performance HEPA filter (replace annually) Poor air quality may require more frequent replacement High Performance HEPA Filter removes 99.97% of all particles greater than 0.3 microns from the air Effectively filters out smaller particles such as dust, pollen, mold spores, and allergens. Contains 2 Antibacterial/Antifungal Multi-filters (replace every 6 months*) and 1 High Performance HEPA filter (replace annually*). *Poor air quality may require more frequent replacement