ULTRX™ Type 4X Enclosures Hoffman ULTRX type 4X enclosures provide outstanding protection against corrosion and the elements. The clean line design is molded fiberglass that makes them a stylish and esthetically pleasing enclosure. These enclosures feature hidden hinges, a padlocking capability for security, and flexible internal mounting options. Exterior surface painted light gray acrylic enamel for enhanced UV protection.