1. This electrical adapter is designed for connecting American 7-way style connector on vehicle to European 7-way round on trailer 2. Fast, easy plug-in installation, minimize the hassle of installing any new wiring inside, no other adapters needed 3. Included a dust cover on the European style 7-pin plug side to keep your connector clean when not in use 4. This single-function adapter transfers the power to trailer with L/R turn signals, taillights & electric brakes 5. Wiring USA 7-pin vehicle-end connector to trailer with EU 7-way round pin trailer wiring