That is a "vexon" file used to metal finish or just plain file sheet metal to cut high spots or find where the high and low spots are.
It is a good tool to have, but it likly will not be used much by the beginer.
If you wanted to really take your time and learn the art of metal finishing, it would be time well spent. The term "metal finishing" gets lost in the translation sometimes. Many think it is simply shaping the metal prior to applying plastic filler. But true metal finishing is repairing the damage (or creating a new panel) without any plastic filler at all. Repairing a piece of stainless steel molding and polishing it would be the ultimate example of metal finishing.
