This is a lot of 12 assorted Sun-Tec Mitutoyo Hardness Standards, used in different industries for testing hardness most often associated with Rockwell Hardness Testing.  All of the blocks appear to be in good shape, as you can see most of them have previous marks from testing but still plenty of room on all of them for additional testing.

There's a mix of circular and square standards, total weight of all of them is just under 6 pounds.

All standards are listed below with the details printed on them, all of the share the same common text: SUN-TEC HARDNESS STANDARD along with Mitutoyo printed on the top.

Listing Includes: 

• Squares Shaped Standards
• 31.8 HRBW +/1 2.5
• 55.2 HR30TW +/- 1.5
• 67.2 HR30TW +/- 1.0
• 76.2 HRBW +/- 2.5
• 90.0 HRBW +/- 1.0
  
• Circlar Shaped Standards
• 33.1 HRC +/- 1.0
• 53.3 HR30N +/- 1.0
• 57.1 HRC +/- 1.0
• 68.0 HRC +/1 0.5
• 74.8 HR30N +/- 1.0
• 81.6 HR30N +/1 0.7
• 81.7 HR30TW +/- 1.0