Holmes  Hepa-Type Tower Air Purifier with 3-Speeds and Quiet Operation, HAP412BNS 3-speeds. Intended for rooms up to 120-square feet Hepa-type filter removes up to 99-percent of airborne particles as small as 2 microns Filter is fortified with Arm and Hammer baking soda to eliminate odors Quiet operation; optional Ionizer; AHAM certified and UL listed Filters: Any Holmes AER1 Series, Holmes HAPF30D-U2 HEPA Type Filter, or Holmes HAPF300D-U2 TRUE HEPA filter