This trailer lighting adapter is used to convert a tow vehicle that has a 4 flat connection to a trailer that uses the 7RV. In this case you have a tow vehicle that is NOT equipped to tow a trailer that has electric brakes. The trailer uses the larger 7RV (or 7 spade) connector because it needs the extra wires to run all of the lights, electric brakes, and the charging for the break away battery. The tow vehicle is only equipped to run trailer lights only. Using this adapter will allow the tow vehicle to operate the trailers lights ONLY, no brakes. The extra wires you see are available if you wanted to hard wire the tow vehicle to be able to have an electric brake controller. If you use this adapter with out hooking up the extra wires (and installing an electric brake controller in your vehicle) it will allow the lights to work on the trailer (brake light, running light, and turn signals).
