The TowSmart 4-Wire Flat to 7-Blade Connector is the quickest and easiest way to make electrical connections when hauling a trailer that has a different wiring configuration than the vehicle. The 4-Wire Flat portion of the pre-wired connector attaches to an existing 4-Wire Flat on the tow vehicle to provide taillights, brake lights, ground and turn signals.Remaining wires attach to electric brake, auxiliary, and reverse light functions.