Filter free and quiet operation, 1 gallon (3.79l) tank capacity, up to 20 hours runtime for medium-sized rooms, adjustable humidistat, visible cool mist, empty tank light indicator, automatic safety shut off. This humidifier is designed for quiet operation and to disperse a cool and visible mist. Improves the air quality in your home and protects your family from the effects of damaging, dry air, especially during the harsh winter months. Helps relieve cold, flu and hay fever symptoms as well as reduce static electricity. Backed by a 1-year warranty against defects.