Pictek Ultrasonic Humidifier Air Purifier with Cool Mist, 12 Hours Continuous Working Time, Auto-Off, LED Night Light, Whisper-Quiet for Home Bedroom Office with Large Water Capacity 2.5 L Providing longer continuous working time up to 25 hours depending on setting & atmospheric conditions, designed with a adjustable knob Please do not add perfume, essential or other corrosive substances into the water tank Auto shutoff safety sensor: With intelligent monitoring technology, it will shut off automatically when water is used up or the water tank is removed It creates romantic ambiance & lights up darkness, some children are afraid of staying in the dark, the nightlight design could make them feel safe