Clear TPX (polymethylpentene) cylinders are non-wetting to prevent a concave meniscus, making the raised numeral, single scale graduations easy to read. They are shatter-proof with a wide octagonal base to prevent tipping and rolling. Superior chemical resistance and safe for use to 175C (350F) make them a great value. Steam autoclavable at 121C (250F). Made of TPX Brand PMP for easy viewing.