The SU-4010 Dual Mist Humidifier is great for homes that like to choose and change their surroundings. The SU-4010 can convert from ultrasonic to steaming humidifier easily, with the switch of a button. There is a dual nozzle so that you can cover more space, up to 500 square feet of space to be exact. The SU-4010 is energy efficient and only uses the power of two light bulbs! The longer power cord allows you to put the humidity where you want it, as do the adjustable nozzles. The SU-4010 features an ION exchanger and will demineralize our water to remove calcium and magnesium from your hard water, preventing white dust particles from depositing in your air.