Amazon.com: Oyviny 5 Way Flat Trailer Wiring Harness Plug with 22 inch Wire Lead Trailer End Durable 5 Pin Male Connector Trailer Light Wiring Harness Extension for Trailer RV Boat Color-Coded Waterproof :
Choosing the right connectors for your trailer wiring
Trailer Wiring Diagram - Wiring Diagrams For Trailers