Dynamic electronically assisted electrostatic air cleaner. Operates on 24 volt transformer (not included). Includes one carbon style filter media. This air cleaner fits in the place of your existing 2 inch thick disposable filter. Simple to install and only requires a small 24 volt transformer to power it up. Maintenance consists of replacing the 2 filter medias every 30 to 90 days, depending upon your environment. Carbon insert absorbs odors while cleaning the air.