These Nalgene™ polymethylpentene beakers have the transparency of glass, excellent chemical resistance, and remarkable heat tolerance - can be used continuously at 150°C with intermittent service to 175°C. All size beakers have easy-to-read silkscreened graduations, catalog number, size code, resin code, maximum use to temperature and no flame symbol. Autoclavable. Not for use on a hot plate. Meet the ISO/DIS 7056 International Standards for Laboratory Plasticware Beakers.