The Sunpentown dual mist humidifier comes with an ion exchange filter to deliver a moisture output of 400 cubic centimeters per hour. It can humidify rooms from 300 to 500 square feet. This humidifier is capable of dispersing both hot and cool mist. Its split nozzle disperses moisture in 2 directions to cover a wider area. Its ion exchange filter de-mineralizes hard water to remove calcium and magnesium. This process brings down the risk of scale formation to increase the life of the humidifier. This Sunpentown ultrasonic humidifier has a removable, transparent 4-liter water tank with a refill indicator for your convenience. The warm and cold mist humidifier has adjustable settings to regulate the mist conditions. It has 2 power levels and a single speed setting. This humidifier operates silently. A safety device prevents overheating.