Arlington's non-metallic enclosure boxes now MEET NEMA 3R requirements for outdoor use. They’re the perfect solution to protecting and securing power backups, security devices and other valuable equipment indoors or outside. Made of heavy-duty, UV rated non-metallic material, and available in three sizes - our boxes are NEMA 3R rated for outdoor use when mounted with the hinge on top. The back plate allows an installer to mount components to the plate even after the enclosure box is mounted. Changing batteries or doing maintenance is easy just by removing the plate. Arlington’s enclosure boxes are ‘lockable’ via a knockout on the front of the box for a cam lock or a latch that holds a padlock.