3 microns and larger. Independently tested and AHAM Verifide to circulate and filter the air in your room 4. Odor Reducing Pre-Filter A 4x/yr. Odor Reducing Pre-filter (HRF-AP1 or HRF-APP1) 4x/yr. Independently tested and AHAM Verifide to circulate and filter room air up to 4.8x per hour in a 310 sq. ft room (Based on 3rd party independent CADR testing for the smoke CADR value when operated at the highest level. ).
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