Installation is as easy as drilling a 1-1/8" hole, inserting the socket body, tightening the locking nut, and connecting the wires. Constructed of injection molded nylon and ABS with stamped brass contacts. Maximum: 12VDC, 16A. Includes all mounting hardware and wire connectors. A 1-15/16" B 1-1/2" C 1-1/16"