Air-O-Swiss AOS 7135 Refurbished Ultrasonic Humidifier - Warm and Cool Mist Humidifies the air in rooms up to 650 sq ft (60m2) Make the choice of cool or warm (104-degreef (40-degreec)) humidification Sleep mode: the unit pre-determines a comfortable night humidity level (timer = 8 hrs, warm mist on, itc on) Industrial strength titanium membrane surface, the quality of which guarantees fast dispersal of mist into the air, ensures long lasting use Includes demineralization cartridge and Hydro Cell