Captures up to 99.97% of common household particles as small as 0.3 microns such as dust, pollen, tobacco smoke, and pet dander. Helps capture airborne viruses and bacteria. The carbon pre-filter captures larger airborne particles and helps remove common household odors. Electronic indicator reminds you when to check the HEPA filter and when to replace the carbon pre-filter. Electronic push button controls, 3 cleaning levels.Replacement Pre-filter: HRF-AP1 or 38002.ARB Certified to comply with the federal ozone emissions limit. AHAM Certified for use in rooms up to 200 square feet.