Holmes HAP242U HEPAType Tower Air Purifier This Holmes tower air cleaner HAP424U is stylish and functional. It utilizes a HEPAtype filtration which helps remove up to 99 percent of airborne particles as small as two microns from the air passing through it. Filtered particles of this size include household dust pollen mold spores and pet dander. The slim tower design allows placement in almost any area of the room. Arm and Hammer enhanced filter helps eliminate common household odors. 3 speed settings provide options for different conditions. Optional ionizer naturally freshens the air. Filter reminder dial to keep track when the filter change is needed. Slim tower design. Quiet operation. Recommended for rooms up to 180 sq ft. 12ft x 15ft.