The Dyson Purifier Cool™ Gen1 purifying fan automatically senses, captures and traps pollutants to purify your whole room¹, while removing 99.97% of particles as small as 0.3 microns.³ ¹Tested per Dyson internal test standards for whole-room air projection (DTM108) and purification coverage (TM-003711). ²Particle challenge by DEHS oil specified in EN1822 within a chamber specified in ASTM F3150. Tested in Max Mode for whole machine efficiency above 99.95%. Gas capture rate vary. ³Tested per ISO 29463.