Cool mist humidifier is maintenance-free, mists quietly without white dust. With its patented carefree design, this evaporative humidifier's unique PermaWick filter and other key components are treated to be antimicrobial, inhibiting the growth of bacteria, mold and fungi. And its exclusive regulated release system eliminates stagnant water that can breed harmful germs, as top-down water dispersion evenly disperses water from the top over the entire wick, reducing mineral build-up. PermaWick filter never needs replacing. Adjustable humidistat maintains your desired comfort level. Two-speed whisper quiet fan, power and humidity indicator lights and auto shut-off.