Shop Nilight 7 Pin Round to 4 Pin 5 Pin Flat Blade Trailer Light Adapter 2 in 1 Trailer Plug 7 Way blade to 4 Way 5 Way Flat Trailer Connector Plug for Trailer Tow Hitch Car RV Boat Truck in high quality, support 2 Years Warranty. Combines 4 way plug with 5 way plug, and can be used by most trailers, allowing for versatile towing options.