Made of high quality, amber colored Borosilicate glass Amber color offers protection from UV Rays 500ml capacity Includes polypropylene stopper Perfect for any science or home laboratory 500ml capacity. This Volumetric flask is made of high quality, amber colored Borosilicate glass, and includes a polypropylene stopper. Flask stands 10.25". Base is 4" in diameter. Eisco Labs Borosilicate glass has the following heat tolerances: Strain Point -515°C | Annealing Point 565°C | Softening Point 820°C.