Patented design provides simple, goof-proof installation and allows the installer to adjust the box to any thickness with the turn of a screw. Clip the included bracket onto any stud, mounts square and secure every time. Securing the bracket to the stud ensures that the box will not move. Comes preset at 1/2". 3" depth x 5-5/8" x 3-5/8". Satisfies NEC 370-20. UL Listed 5Z74 and classified 2 Hr W/C.