Three piece Volumetric Flask set made of high quality Borosilicate 3.3 Glass. Includes three flasks with 50ml, 100ml & 250ml capacities. Class A Tolerance, as per ASTM E288 standards. Each flask includes a glass penny stopper, and features a single, white graduation line. Set is packaged in a custom fit, thick foam casing, for safe storage and worry free transport.Measurements:50ml) 6.3 tall, 2 wide base, 16mm diameter neck. #13 Stopper.(100ml) 6.75 tall, 2.25 wide base, 16mm diameter neck. #13 Stopper. (250ml) 9.5 tall, 3 wide base, 18mm diameter neck. #16 Stopper.Microwavable and autoclavable, with superior chemical durability. Low temperature gradient- can withstand high temperatures & thermal shocks. Eisco Labs Borosilicate glass has the following heat tolerances: Strain Point -515°C | Annealing Point 565°C | Softening Point 820°C.Eisco Labs proudly manufactures its own products using state-of-the-art equipment, and following the highest standards of quality control.Each product is carefully designed by a team of laboratory professionals and experienced engineers with quality and durability in mind. They are manufactured with only the highest grade, raw materials and according to international quality standards to ensure that they can withstand use in even the toughest laboratory environments.