The TowSmart 7 Blade to 4 Wire Flat Trailer Light Adapter is the quickest and easiest way to make electrical connections when hauling a trailer that has a different wiring configuration than the vehicle. The adapter connects taillights, brake lights, ground, and turn signals. The single housing design plugs into your vehicle's electrical socket. It provides an ergonomic, durable plastic construction that is corrosion-resistant to withstand extreme weather. For the safest towing, ensure all functions are properly equipped. Helps make electrical connections between vehicles and trailers Plug-in, hassle free connection - no rewiring required For connecting trailers with a 4-Wire Flat to a 7-way blade tow vehicle