Object is a photo mask for a die of chips. It is enclosed in a plastic box. On both sides of the box are red paper labels with many initials for inspections carried out.
Identifying Numbers
Other number
371165
Scratched into reverse side
Other number
371354
Written on top red label
Other number
372332
Written on bottom red label
Other number
5 02-10-86 39 10-15-71 4
Etched on top edge of glass
Other number
MK04116-01F7
Etched on top edge of glass, also on both red labels