The Winix U450 True HEPA Air Purifier is ready to go with its all-in-one filtration cassette that is packed to the brim. It includes a washable anti-microbial pre-filter, a 99.97-percent efficient True HEPA filter, CleanCel-treatment, advanced odor control and PlasmaWave technology, providing 5-stage superior control. It creates pure air like that found in nature without creating harmful ozone that can cause problems for allergies or asthma. This PlasmaWave air purifier is designed for optimal use for large living spaces, large offices, or bedrooms. It is also helpful in aiding people who have health issues as they help in cleaning the tiniest particles in the air. The Winix U450 True HEPA Air Purifier gives you the ability to breathe in more of the pure oxygen your body needs and less of the harmful pollutants that come along with it.