7 Wire to 7 Way RV Trailer Light Custom Plug Wire Harness Electrical Quick Converter Adapter with Mounting Bracket, Truck End Quick-Install 7 Prong Universal Pigtail Wiring Harness. Commonly Used with T-Connectors or Tail Lamp Converters with 4-Way Flat Car End Connections 4 Wire Flat to 7-Way RV Blade Round Includes Mounting Bracket and Hardware Allows the User to Create Custom Plug-in Wiring Systems For any Towing Situation.