Amazon.com: Oyviny 4-Way Flat to 7-Way Round Blade and 4 Way Trailer Wiring Harness Adapter Vehicle-Side 4 Pin to Trailer-Side 7 Pin and 4 Pin Dual-Output Connector with Mounting Bracket for Truck
Amazon.com: Tow Ready 20320 4-Flat to 6-Way Round Pin Connector Adapter : Automotive
Reese Adapter 7 Way Round to 4 Way Flat in the Trailer Parts & Accessories department at Lowes.com
TowSmart 7-Way Blade to 4-Way Flat Trailer Light Wiring Adapter 1415 - The Home Depot
Amazon.com: Reese (118710) 7-Way European Style Round Pin to 4-Way Flat Adapter : Automotive
Hopkins Mod 4 Wire Flat 7 RV Round in the Trailer Parts & Accessories department at Lowes.com
MaxxHaul 70086 7-way Round To 4-way Flat Trailer Plug Adaptor with 18-in Flexible Cable Which Extends To 36-in in the Trailer Parts & Accessories department at Lowes.com