Chrome-plated polarized 5 contact trailer socket.  For automobile, truck, marine, and RV use.  Spring loaded cover holds plug in place and keeps out elements when not in use.  Heavy round brass contacts capable of 15 amps per contact.  Two 3/16" mounting holes, 1 3/4" on centers.  5th pin allows for the addition of an auxiliary electrical line.  Use with trailer plug TC-72555.