What is vicks mini coolmist ultrasonic humidifier quiet operation the ultrasonic technology generates a quiet, soothing mist to aid breathing and sleep during coughs, colds, and congestion. Safety assured with cool mist technology, this humidifier is safe for home use in adult, child, and baby bedrooms, eliminating risks of burns. Dual aromatherapy two slots for essential oil vapopads provide extra comfort with menthol vapors to clear airways. Adjustable, directed mist a 180 degree nozzle lets you adjust and direct the mist to maintain ideal 40 60% humidity. Long lasting performance the 1.8 liter tank runs up to 24 hours before refilling, covering rooms and bedrooms up to 15 sq. Meters.