This volumetric flask set includes three Class B borosilicate glass flasks with glass stoppers in sizes of 250mL, 500mL, and 1000mL. All flasks comply with ASTM-E288 standards with a tolerance of ±0.100mL. Each features an easy-to-read blue graduation mark and is calibrated to contain. The borosilicate glass has heat tolerances including a Strain Point of 515°C, Annealing Point of 565°C, and Softening Point of 820°C. This set provides the three most commonly used volumetric flask sizes for quantitative chemistry and analytical laboratory work.