This is a Cole Hersee 4-pole socket.  Part #1257.
With special housing that protects terminals from roadsplash.  Exposed screw terminals.
Normally used with a trailer where limited functionality (taillights, brake lights) is needed. Ideal for boat trailers, or RVs
towing a car on a flatbed trailer. Diecast metal housings. Screw terminals accept up to 12AWG wire. Replaceable interiors.

Brass split-pin contacts are aligned to assure proper contact and minimal voltage drop. Spring-loaded socket doors, plug
locks securely into the opening. Wiring codes are identified on the insulator. Two mounting holes on the flange 17/64"
(6.7mm) diameter, 2 15/16" (74.6mm) on centers. Mount through 1 3/8" (34.9mm) diameter hole.

NOS in original box!!  Will combine shipping with multiple purchases!  Will ship internationally using Ebay's Global Shipping Program.  Please note Ebay will charge and collect sales tax based on your state.