Humidifiers help keep living air moist during cold winter months. Using ultrasonic vibrations, water is converted into a micro-fine mist that gently (but efficiently) emits moisture into a room. This humidifier has an Integrated filter housing that contains a protective Nano-silver material that helps prevent bacterial, calcium, and lime build-up. This means that the ultrasonic warm or cool mist that the Venta-Sonic VS 100-536 produces is both comforting and healthy. Select cool or warm mist Integrated Hygrostat controls humidification intensity Removable Transparent tank with handle and visible water level Ultra-Quiet operation Easy to clean and maintain Practical control panel Designed to humidify a room up to 600 square feet [$99.99]