The Philips 800 series air purifier - a small but effective device that brings clean air into your home in a compact and simple way: the intelligent automatic air purification mode, controlled by a professional sensor, automatically detects and reacts to even the smallest changes in the air. The four-level color display for real-time air quality, from blue (good) to red (poor), gives you confidence about the air quality in your home. In sleep mode the indicator lights are dimmed. The air purifier works almost silently at 35 dB and provides clean air while you sleep. Ideal for use in the bedroom or children's room.