This part is for a vehicle to vehicle towing kit. What this basically does is, say you have an RV or motor home or pickup truck and you're going to towing another vehicle on all four wheels you're going to need this wiring harness to make the lights on the towed vehicle work with the towing vehicle. We'll start by showing you the different components of this kit, it's really pretty simple if you break it down. First the connection here is a traditional four pole flat. So you have your four basic signals, your ground, running lights, left turn and right turn. You also have plenty of harness to attach this on the towed vehicle. When you make your connections on the towed vehicle itself, you have to install these diodes here. At the point where you make your connections on your vehicle whether it be your left or right turn or the running light circuit you will have to install these diodes.To give you a couple of quick notes about these, what happens is they do go in a specific direction in the wiring harness. to keep it simple basically the single prong here is listed as out, that goes onto the taillight itself out to the bulb. Then you get the two inputs here, one of the inputs is going to be the wire you just cut because you're going to splice this in between the two. It does not matter which one, the wire is going to come in one side and out the other. This other pin here is going to provide input from your trailer harness coming from the towing vehicle itself. So for instance you would take your green wire here and run it to the other open end and it will go out and power your taillight being towed down the road by the RV. As you can see there's 4 diodes and there's a reason for that. There's going to be one for the left and right turns, and both turn signals are going to have there accompanying running lights. So you're going to need a diode for each of the running lights. Now we've opened up a small bag of parts which contains all the spade connectors needed to d...