4-step color indication for real-time air quality ranging from blue (good) to red (poor), gives reassurance about the air quality in your home. Effectively removes 99.5% nano-sized particles as small as 0.003um (800 times smaller than PM2.5). including PM2.5, pollen, dust, and pet dander, etc. Removes 99.9% virus and 99% bacteria. Make sure you breathe healthy air even during heavy pollution season. Intelligent auto purification mode, powered by the professional-grade sensor, automatically senses, and reacts to even the slightest change in the air. In sleep mode, display lights are dimmed and the purifier operates in near silence for clean air while you sleep, as low as 35db(A)*. Perfect for using in the bedroom or baby room.