Rosahl PD3 is a compact electric dehumidifier that uses an ionic membrane to electrically dehumidify enclosures of less than two litres in size. The PD3 is 75%smaller than a AA battery and is installed through a 12mm diameter hole in the enclosure. It is the World’s smallest electric dehumidifier in commercial use. Larger sizes are available for enclosures up to 4m³.