The BISSELL® air400 Air Purifier from is clean air made easy for your guests, students and staff. There are odors, allergens, dust, and other things we can't always see in our air that needs to be cleaned. The air400 CirQulate® System also uses particle sensor technology to monitor your indoor air and communicate your home's real-time air quality through three distinct colors and a numerical reading. It captures airborne particles and odors with three stages of filtration. SKU 2479B