seemingly otherwise blank coin with countermarks?

I picked this up recently, at first i assumed it was junk because it looks like it's worn flat, but looking closer it appears to have countermarks on it.  the back is entirely blank.  The approximate diameter is 30.4mm.  is it just trash like I first thought?  Or something else?

Thanks in advance.

I would like to preface all of the following  by making it clear that I am NOT an expert nor professional…

By my assessment, it would seem to be the calibration or quality control item…