The Honeywell Air Genius 4 Compact Air Purifier features 4 levels of cleaning power and a patented ifD® advanced filtration system that provides exceptional air cleaning performance for medium rooms of 250 square feet. The patented ifD® technology uses electrical power to help capture up to 99.9% of the following microscopic airborne particles: dust, pollen, pet dander, dust mite debris and smoke.1 As air exits the purifier, molecules are charged to create ions which attach to these particles floating in the room. Those particles get pulled back into the air purifier and pass into the electrically charged ifD® filter that is permanent and washable.