DIATEST Precision Bore Gage Set w/ 11 Heads, 11 Setting Rings & Wood Case

I am selling my entire machine shop and I had this in my inspection area.  I do not recall ever using this. I don't know how it works or if  all the needed parts are in the set.  It looks brand new. The gage does work freely.  It seems to be more complete than any other that is listed for sale.