This electrical converter allows to change a European style 7-pin vehicle adapter to a American style 4-pin flat Plug and play design, minimize the hassle of installing any new wiring inside, no other adapters needed Included a dust cover in the American trailer 4-pin plug side to keep your plug clean when not in use Converter with the function of combining 'stop' signal to the two-wire system US vehicles Wiring European 7-pin vehicle connector to trailer with US 4-pin flat trailer wiring