Description_x000D_ General description_x000D_ • Complies with ISO 1042 and DIN 12664_x000D_ • Calibrated to the tolerance required by the United States Pharmacopoeia (USP) which are tighter than those of ISO/DIN standards_x000D_ • Manufactured from borosilicate glass with an amber coating on exterior surfaces to facilitate use with light sensitive solutions_x000D_ • Each flask is laser etched with an individual serial number, batch code and date of manufacturer_x000D_ Legal Information_x000D_ PYREX is a registered trademark of Corning, Inc.