Ultra Glow Light Changing Humidifier + Diffuser. Essential Oil Two Ways: Diffuser - add essential oils directly to water tank. Oil Tray- add essential oils to the tray. 7 color changing tank lights - Independent light settings; Rotating colors, Single color, Off, and Dim option. Adjustable mist outlet. Easy to fill & clean- wide opening & cleaning brush. Variable moisture output settings. Auto shut off when empty. 1/2 gal. capacity, 24 hour run time, Small rooms