Borosil Cylinder, Class A, Single Metric Scale with Pour out and Hexagonal Base (3026)3026 Borosil Cylinder, Class A, Single Metric Scale with Pour out and Hexagonal Base Complies with ASTM E 1272 Calibrated as per Class A tolerances required by the United States Pharmacopoeia (USP) that are tighter than those of ISO DIN standards Each cylinder is engraved with a unique serial number, and comes with a Certificate of Calibration traceable to national standards Graduations in Amber enamel Manufactured with chemically resistant 3. 3