Vicks V790-N Germ Free Humidifier helps provide temporary relief from cough and congestion for better comfort. Also helps you breathe better and sleep more comfortably. UV technology kills up to 99.999% of bacteria mold fungus and virus in the water after 2 hrs of continuous use. This provides the assurance that the moisture emitted from the unit is virtually free of germs. Patented Germ Killing Technology kills up to 99.999% of certain bacteria mold fungus and virus in the water; Quiet operation; Adjustable moisture control; Medicine cup for use with liquid inhalants; 2.0 gallon water tank; Runs up to 24 hours per filling; Great for medium to large size rooms.