These are the components for one side of the rear. As you can see, it is a very simple setup to use--but it took a bit of engineering to make it this simple. Bolt the air spring to the upper adapter and insert the air fitting. Now's the time to make sure this is all snug and air-tight. The threaded rod is used to retain the top. Screw the rod into the air spring assembly and make sure it is fully seated.