Ok, I ca n't figure out what this little square metal part is that came in the box with my new smoker. It has two edges that are bent up. Is this just an accidental random piece of metal that got mistakenly thrown in the box, or does it have a purpose with the smoker? It does not seem to 'fit' anywhere on the smoker. I did get the little round raised perforated grate that goes inside the smoker to raise the fuel up off the bottom a bit. But what's this thing?