High quality Borosilicate Glass 10 ml capacity, 0.05 ml graduation lines Glass Key Stopcock 18.5" tall, 0.4" diameter. Class A, DIN 385 Compliant Class A, Accuracy as per DIN ISO 385 standard. Burette is made of high quality 3.3 borosilicate glass. Glass key stopcock. Capacity 10ml Sub. Div.0.05ml Tolerance ± 0.20ml Eisco Labs Borosilicate glass has the following heat tolerances: Strain Point -515°C | Annealing Point 565°C | Softening Point 820°C. Calibrated for delivery. 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.