Hexagonal Hollow Stopper with Flat Bottom, 10/19, Borosilicate Glass

This hollow glass stopper is made from 3.3 borosilicate glass and features a hexagonal top with a flat bottom. The stopper has a 10/19 cone size and measures 1.25 inches in total length with a 0.5-inch wide top. The borosilicate glass construction is autoclavable with superior chemical durability. Heat tolerances are: Strain Point 515°C, Annealing Point 565°C, and Softening Point 820°C. Hollow stoppers are lighter than solid versions and are used where a standard ground glass closure is needed without excessive weight.