Mounting plates are used for mounting equipment up off the back of an enclosure. Steel plates are all 3.3 mm (0.13 in) THK hot dipped galvanized material. Aluminum plates are 3.3 mm (0.13 in) THK material up to and including 304.8 x 304.8 mm (12 x 12 in) size. All larger sizes are constructed of 4.8 mm (0.19 in) THK aluminum plate.