nVent HOFFMAN UU504030W Ultrx Enclosure Window Door Type 4X 500 mm x 400 mm x 300 mm provides outstanding protection against corrosion and the elements, the clean lines and molded, embossed design of ULTRX fiberglass enclosures make them the most stylish and aesthetically pleasing of their class. These enclosures feature hidden hinges, a padlocking capability for security, and flexible internal mounting options.