Weird metal piece included with the new truetrac diff

Ok so I spent a couple of minutes on line And I see how the TruTrac works.
The slug is a spacer.
If you're using the tapered bearings, use it to to determine if the adjusters will work. Adjust the slug length if necessary, slam it together with the slug inside the trutrac
If you're using the Greens, throw it away.
Yes its just that simple.