Tirol 7 Pin Blade to 6 PIN Round Trailer Adapter Trailer Light Plug Connector 12v Towbar Towing 7 Way Flat Pin to 6 Way Round Pin Trailer Wiring Adapter Plug. Easily converts a 6 way round plug to the 7 way flat pin plug. 7-Pole Blade RV Trailer End Connector, Brass contacts to prevent corrosion. Accepts the 6 way round plug directly into the back of the 7 way plug. Features: Connect the major vehicle and the additional trailer.