Check the listing for details. Pollak 6-Way Round Trailer Receptacles, Spring Covered Solid Cast Zinc Circular. Condition: New. Listed at 12.99 USD. 3172ZC5A.40 New Pollak 1" Socket Diameter 6-Way Round / Circular Trailer Receptacles, Spring Lid Covered, Solid Zinc Housing, Brass Terminals. Each bid quantity is for One (1) Receptacle. You may bid / buy any number, up to the total quantity available above. These were purchased at an industrial liquidation several years ago, and they were brand new in an unmarked box. Seems to be an older / better version of these than what we've found recently. Made in the USA (imagine that)! According to the calipers: Overall width: 3.625" / 92.07 MM Overall height: 2.378" / 60.41 MM Mounted depth: 2.285" / 58.05 MM Mounting Holes: .271" / 6.90MM Spaced 2.905" / 73.79MM On Centers Rear / trailer plug hole diameter: 1.012" / 25.71 MM Front / vehicle wiring hole diameter: .617" / 15.69 MM