7 Way Round to 4 Pin 5 Pin Flat Trailer Wire Light Adapter Plug RV Tow Connector - Walmart.com
Amazon.com: YONHAN 4 Pin to 7 Pin Adapter Trailer Light Adapter 4-Way Flat Truck to 7-Way Blade Reverse Plug Connector with Mounting Bracket for Towing Solutions : Automotive
Amazon.com: OPT7 7 Pin to 4 Pin Trailer Adapter with Secure Tab, 7 Way Blade to 4 Way Flat Trailer Light Adapter, Connector for Trailer Tow Hitch and Redline LED Tailgate Light Bar : Automotive
Hopkins Towing Solutions 6-Round to 7-Blade Adapter, CA Prop 65 Compliant, 47435 at Tractor Supply Co.