This 1L PYREX® Class A volumetric flask with a glass standard taper stopper is made from low actinic stained glass to provide protection for materials sensitive to light. The protective color is an integral part of the flask, which retains its mechanical strength, chemical stability, and thermal resistance. The strength of this flask has been increased appreciably through a machine-blown body to which is sealed a heavy-tubing neck tooled for a No. 22 standard taper glass stopper. The graduation line is sharp and permanent and large white block letters make the inscription easy to read. This Class A volumetric flask has been manufactured to Class A tolerances as established by ASTM E- 694 for volumetric ware, ASTM E-542 for calibration of volumetric ware, and ASTM E-288 for volumetric flasks. Reusable. Material: Borosilicate Glass Code 7740. Capacity: 1000mL. Flask Style: Volumetric. Flask Shape: Flat Bottom. Top Style: Standard Taper Stopper. Neck Style: Long. Stopper Style: Hollow Glass. Flask Feature: Low Actinic. Accuracy Class: Class A. Tolerance: +/- 0.3mL. Standard Taper Stopper Number: 22. Height: 342mm. Outer Diameter: 125mm. Corning®#: 55640-1L.