ISO 12098 - The international standard for trailer connectors
Amazon.com: Zimuqi 4 Way 15 Feet Flat Trailer Connector Jacketed Cable Heavy Duty Extension Standard Pin End Wiring Harness Adapter 18AWG Color-Coded Red Copper Wires for Hitch (15eet) : Automotive
How to wire a trailer plug - 7 pin (diagrams shown) - YouTube
Export Adapter Coil 15 Pin to 2×7 Pin EC15
TRAILER WIRING INFORMATION
Irfora Tirol 7 To 13 Pin Trailer with Cable Adapter Wiring Connector Towbar Plug & Socket - Walmart.com
15 Pin Trailer Connector Wire - China Trailer Connector and Trailer Parts
ISO standards for trailer connectors - Wikipedia
Trailer Wiring Diagrams - Johnson Trailer Co.
ISO standards for trailer connectors - Wikipedia
XM381 - 12 Volt Civllian Truck to 24 Volt Military Trailer Lighting Converters
Hopkins Ford Chevy GMC 7 Way OEM 7 and 4 Way Trailer Connector Kit 40955 Truck | eBay