Hopkins 4-Wire Flat Connector, Vehicle to Trailer Wiring Connector in the Trailer Parts & Accessories department at Lowes.com
Nilight Heavy Duty 7 Way Inline Trailer Plug with 7 Gang Junction Box - 8 Feet, Trailer Connector Cable Wiring Harness with Weatherproof Junction Box Suitable for RV Automotives Cars,2 Years Warranty - Walmart.com
TowSmart 12 in., 4-Way Flat Trailer Wiring Connector 1441 - The Home Depot
Trailer Light Connector 3 Prong Plug 10 inch Wires for Tail Lights