Holmes HAP424-U Air Purifier Purify Technology: HEPA, Ionizer Operates Room Size: 180 sq.ft. Speed Setting: 3 speeds Color: Black Feature: HEPA-Type filter helps remove up to 99% of airborne particles as small as 2 microns from the air passing through. Arm & Hammer baking soda enhanced filter helps with eliminating common household odors. Optional ionizer maintains a room of fresh air by removing odors. There are three cleaning speeds to accommodate for different conditions.