This converts the bar of the cargo carrier from a 2 inch receiver to a 1-1/4 receiver. To start our process, what we need to do is take off the old bar first. That necessitates taking off these four bolts, there are some block nut bolts on the bottom so we will undo those and then we can uncrank the bolts from the top. Like I said before, there are these four lock nuts that have to come off and they just double nut the bolt into place. Now we can take off these four bolts on the top. Once you have the shank uninstalled, were going to slide the new one underneath of it. We put our new bracket in which replaces the old one and put our new bolt in which goes directly in the center. Just thread it in place and hold it. Now we go to the other side. Now we tighten them up. There you have it for part # X12BAR.