Effectively humidifies small and medium rooms up to 500 square feet. Auto-Off function activates when water tank is empty. Ultrasonic cool mist increases moisture in the air for easier breathing and a good nights sleep. Removable 1 gallon tank easily fits under most bathroom sinks. Runs whisper quiet up to 24 hours. Relieves cough, cold, and flu symptoms, as well as nasal congestion, dry cough, sinus irritation, nose bleeds, and dry skin and hair. White Ultrasonic cool mist increases moisture in the air for easier breathing and a good nights sleep. Removable 1 gallon tank easily fits under most bathroom sinks. Runs whisper quiet up to 24 hours. Relieves cough, cold, and flu symptoms, as well as nasal congestion, dry cough, sinus irritation, nose bleeds, and dry skin and hair. Clean control antimicrobial material in the base is proven to help reduce mold and bacteria growth up to 99.96%. Effectively humidifies small and medium rooms up to 500 square feet. Auto-Off function activates when water tank is empty. More energy efficient than a household light bulb up to 45W Does not require a filter.