SciLabware Pyrex Volumetric flask heavy duty class USP/ISO/DIN tolerances

Pyrex; SciLabware 3151/22WC. Class A, works certified - Complies with ISO 1042 and DIN 12664 - Calibrated to the tolerances required by the United States Pharmacopoeia (USP) which are tighter than those of ISO/DIN standards - Each flask engraved with individual serial number and ...Pyrex; SciLabware 3151/22WC. Class A, works certified - Complies with ISO 1042 and DIN 12664 - Calibrated to the tolerances required by the United States Pharmacopoeia (USP) which are tighter than those of ISO/DIN standards - Each flask engraved with individual serial number and supplied with certificate of calibration traceable to National standards - Conformity ‘H’ certified - Manufactured from borosilicate glass for corrosion-free performance - White enamel inscriptions - Polyethylene stopper