Effectively relieve your dry nose, throat, lips, and skin with the virtually silent AIR-O-SWISS 7133 and 7135 humidifiers. Unlike any other humidifier we've seen, these ultrasonic humidifiers offer you the choice of dispersing warm or cool mist. Their sleek design with easy to use controls - either digital or manual - and a transparent removable cover make these units some of our favorites! AIR-O-SWISS has created healthy home humidifiers that prevents germs, bacteria and white dust by including a demineralization cartridge and ionic silver stick.