7-Way Flat Pin to 7-Flat Pin Adapter w/LED Lamp Out By-Pass for European Vehicles. For Vehicles with Trailer Lamp-Out Sensors such as: Audi, Mercedes-Benz and Volkswagen, and vehicles with a Factory Tow Package.
Plugs into 7-way round RV-style socket
Eliminates false 'trailer lamp-out' indications when towing a trailer equipped with LED lights