Product Material Conical Flask is made of high quality 33 borosilicate glass GG17 laboratory grade glassware Product Features High temperature resistant acid and alkali resistant with good stability Lab tested Export quality Conical Flask conical perfect for any School College Laboratory Package Includes Pack of 6 Conical Flasks 250 ml with Graduation Marks Design The surface is smooth and beautiful Conical Flask is suitable for mixing heated liquids and the scale is clear and easy to read Easy to clean suitable for home brewing making drinks measuring large volumes of liquid making soap experiment science fair project etc