Grade AS 1 gage block supplied with a Mitutoyo certificate of inspection that the block meets American Society of Mechanical Engineers ASME B89.1.9 2002 standard for flatness, length, parallelism, and surface finish
Ceramic block for dimensional stability and thermal expansion resistance
Square base for accurate wringing, attaining a height reference standard, and for the ability to make a dedicated inspection jig
Nominal length in inches indicated with laser etched, black characters
Identification number etched in block for traceability