Ideal for mixing solutions, titration experiments, yeast culturing, chemistry experiments and more, these Erlenmeyer flasks are manufactured from Class A, Type 1 borosilicate glass that meets ASTM E1404, DIN 12380 specifications. They have a heavy-duty beaded rim to help prevent breakage and approximate graduations indicated in easy-to-read, durable white enamel. Able to withstand temperatures of -50 to 550°C (-58 to 1022°F), they are autoclavable for sterilization.