4-stage True HEPA Filtration: Effectively removes at least 99.97% of particles as small as 0.3 microns, including allergens, such as pollen, dust, pet dander, and smoke in rooms 150-250 square feet Antimicrobial HEPA treatment: Applied to the True HEPA filter inhibits the growth of odor and stain-causing microorganisms to extend the filter lifespan Monitors occupancy and air quality: the air purifier that works harder when you need it powered by EnviroSmart™ Technology Wall Mount: With a slim profile, seamlessly integrates in your space creating whole-room circulation. Floor stand accessory and ADA complain recess kit also available Built to Last: Designed and engineered for long term use backed with 3year warranty