PYREX 500 mL Class A Certified and Serialized Volumetric Flasks, with Glass Standard Taper Stopper Each

These 500 mL PYREX volumetric flasks are calibrated to Class A tolerances in accordance with ASTM E-542 and E-288. Supplied with No. 19 Standard Taper glass stoppers. For replacement stoppers see No. 7650. The graduation line is sharp and permanent and large white block letters make the inscription easy to read.Tested and calibrated in an ISO/IEC 17025 certified laboratory.