This humidifier was used a couple of times only. It is like new, in it's original box and still under warranty. It is in pristine condition, as you can see from the pictures. It is an ultrasonic humidifier, with both cool and warm mist options, with negative ions option as well. It is designed for a big room (upto 700 sq ft). It has automatic shut off when running out of water. It has a filter, but it doesn't need to be changed. It has an aroma box as well, for use with essential oils. Since I bought it for $65 and it's like new, you're really getting a bargain here!