Round 7 Way to Flat 4 Way Boat Trailer Plug Adapter with 18 Inches of Wire - White's Marine
Amazon.com: Oyviny 5-Way Flat Trailer Wiring Harness Female Plug Connector with 31 inch Wire Lead Vehicle Side 5 Pin Plug Extension Cable with Brass Terminals for US Standard Trailer : Automotive
7-Way Flat Pin to 5-Way Flat Connector Adapter - Center Pin is Backup - Adapters - Wiring, Adapters, Connectors - Products