Made of high-quality borosilicate glass that can be heated directly in an open flame. Use a #6-1/2 stopper for this glass flask. Approximately 14 cm tall with 8.5 cm diameter. Neck inside diameter is about 30 mm. Imported. HST brand.
this glass is very strong and unbreakable, i accidently dropped it and it was fine. but of cource if you smash it it will break but it is over all a great flask, and it heats up well