I am selling my Philips Comi Air-purifier. I only used it in the bedroom at night. (Philips Combi air purifier and humidifier AC4085/00 CADR 270 m³/h PM2.5 removal rate >99% With humidity control) I will offer a new humidifier filter with it including all manual and guarantee paper for 1800 RMB. Bought in 2013 Only used at night Maintained as mentioned in description (weekly cleaning) 3 colors indicate air quality (blue, purple, red) Healthy Air Protect Alert indicates necessary replacement of the filter