Polypropylene cylinder with a blue polypropylene base. No meniscus to confuse readings. Guaranteed to meet accuracy requirements of ASTM Class B, E1272, "Cylinder, Graduated, Laboratory, Glass" and all requirements of ISO Standard 6706 "Plastic Laboratory Ware-Graduated Measuring Cylinders." Large blue base prevents tipping. All sizes have generous pour spout. Molded in translucent polypropylene. Molded-in large, easy-to-read graduations. Can be chemically sterilized without affecting accuracy. Can be autoclaved, but accuracy will be affected. PP resin meets requirements of CFR 21, Part 177.1520 section.