Corning Pyrex 5641-1L Borosilicate Glass 1L +/- 0.6mL Flat Bottom Class B Economy Volumetric Flask, with Glass Standard Taper Stopper Capacity: 1000mL; height: 342mm; outer diameter: 125mm; tolerance: +/- 0.6mL Made from borosilicate glass code 7740 Flat bottomed volumetric flask has a long neck style Supplied with No. 22 standard taper glass stopper Reusable Class B economy flask has capacity tolerances that are twice those specified for Class A volumetric ware