The Walton SF-24 humidifier is a self contained atomizing style humidifier. This model is no longer made but there were 2 different versions of it. One was 120 volt and the other was 240 volt. It had a built in fan assembly on the top to assist in distributing the mist across a large area. Typical applications are photo and test laboratories, produce storage areas and stock rooms. Maintenance on the Walton SF-24 consists of washing the unit out on a regular basis.