The Perfect Aire 1 gal. warm mist tabletop humidifier produces a visible, warm mist, has no filters to replace and has a 1 gal. water tank capacity. The unit has a 12- to 24-hour run time and two settings for high or low output as well as an illuminated output dial. A special night light feature option can be turned on or off with the simple press of a button. The 230w unit has mechanical controls and puts out 1.9 gal. of water per day (10.1 OZ/hour). Warm mist humidifiers add moisture to the air to prevent dryness that can cause irritation in many parts of the body. They can be particularly effective for treating dry skin, nose, throat and lips and can provide temporary relief from cough, congestion and symptoms of the common cold and flu.