Mitutoyo64AAA590 Calibration Set for Shore A Scales with Nominal 30, 60, and 90 Blocks Included, with Mahogany Case Used to calibrate Durometers testers 3 Shore A scale blocks included 2" X 2" X 1/4" block size Blocks are calibrated per ASTM D 2240 Supplied in mahogany case Mitutoyo Calibration set, Shore A, Blocks included: Nominal 30, 60 and 90, Block size: 2" X 2" X 1/4"