This cold mist humidifier will allow you to breathe unparalleled air quality while ensuring quiet operation. Its tower-style construction is ideal for medium to large sized rooms (250 to 700 sq.ft.). Its QuietCare (TM) system makes the engine 30% quieter and maintains a high level of performance. Its cleaning cartridge helps produce a cleaner and fresher mist, while helping prolong the filter life. Replacement filter: HAC-504C (0522004). Protec cleaning cartridge: PC-1C-BX (35115051). 3-year limited warranty.