The 21B-2-4-3 from Calmark Birtcher is PCB-tainer with height of 3.30 mm (0.130"), 1.59mm (0.63") board thickness and 50.8mm (2") length. This PCB-tainer is made of beryllium copper, 1/4H per ASTM-B-194 and has cadmium per QQ-P-416, TYPE 2, CLASS 2 finish. Mounts to the enclosure with standard rivets, eyelets or screws. For sheet metal applications.