Perfect for yeast starters. Can be put on an open flame. Accommodates the No. 7 1/2 rubber stopper. Made of Borosilicate glass (making it resistant to thermal shock, more so than any other common glass). Great for making yeast starters. Boil, cool and ferment starter wort right in the flask!
Borosilicate Glass - Narrow mouth with heavy duty rim, Graduated in durable white enamel.