Pure Cool, the latest purifying fan range of Dyson, senses pollution and allergens, captures them in a sealed HEPA activated carbon filter, and projects purified air around the room. The range offers two options, the Tower Advanced, to be set on the ground and the smaller Desk Advanced, to be set on the desk or similar surface. The LCD on the purifier shows air quality levels in real time, including the data of ultrafine particles (PM 2. 5), allergens (PM10), volatile organic compounds (VOCs) & Nitrogen Dioxide (NO2). The sealed HEPA filter captures 99. 97 percent of allergens as small as 0. 3 microns, making it an ideal air purifier for allergies, pets, dust, pollen and mold spores. The Air Multiplier technology delivers over 77 gallons per second of smooth, yet powerful airflow. Up to 350 degree of oscillation directs airflow where you need it.