Amazon.com: Trailer Socket Converter - MASO waterproof 13 to 7pin towing socket caravan trailer electrics plug adapter suitable for European standard trailer : Automotive
12V 13 To 7 Pin Trailer Socket Adapter Waterproof Truck Caravan Towing Electric Adapter Trailer Wiring Connector Tow Accessories - AliExpress
Thule Adapter 9906 7 pins to 13 pins
Waterproof 13 to 7 Pin Plug Trailer Truck Electric Adapter Towbar Towing Socket - AliExpress