Seven Stages of Purification:The 7-Stages: Activated OxygenUnpleasant odors can be among the toughest elements to remove from the air you breathe. To combat such airborne pollutants, the Summit air purifier utilizes Activated Oxygen (03) to breakdown particulates (such as smoke, household chemicals, and perfumes) at the molecular level. Lingering airborne contaminants oxidize away when coming in contact with the trace amounts of ozone dispersed throughout your home leaving pure oxygen (02) in its place. Such fast acting, deep cleaning power is ideal for smokers looking to bring Rocky Mountain freshness to their home. There is simply no substitute for the Summit. In fact, the Summit's Ozone feature can be safely toggled on and off, giving you the option to use the unit's full cleaning power only when you need it most!