Bottle Reagent, borosilicate glass, wide mouth with interchangeable hexagonal glass hollow stopper 125ml, socket size 29/32-EIS-CH0163B offers a thoughtfully designed, durable resource for hands-on learning. Reagent bottle made with heavy duty borosilicate glass. Bottle has a wide mouth with interchangeable hexagonal glass hollow stopper socket size 29/32 125ml Bottle Reagent bottle made with heavy duty borosilicate glass. Bottle has a wide mouth with interchangeable hexagonal glass hollow stopper 125ml, socket size 29/32. Single Bottle with stopper. Eisco Labs Borosilicate glass has the following heat tolerances: Strain Point -515°C | Annealing Point 565°C | Softening Point 820°C.