Made from 12.7mm wide, 304 stainless steel. Used in manufacturing and maintenance where stringent, corrosion resistant, and low magnetic material is required to check extremely tight tolerances. Contains 1 piece each of 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.10mm, 0.15mm, 0.20mm, and 0.30mm.