DISCLAIMER: I am cleaning out someone's workshop, and I don't know anything about this item. Description and price are based on results of internet search. if you see something inaccurate here please let me know!!
Offers accepted.
This appears to be a 9 piece solid pilot counterbore set, based on listings found at mscdirect.com for very similar ones. The shanks on this set vary from 3/16" up to 1/2" (although the 1/2" one actually measures something in between 7/16 and 8/16"). No mfr mark that I can find on this item. In solidly built wooden box about 3.5" wide, 4" tall.