These 1L PYREX Class A graduated cylinders are calibrated "to contain" (TC) in accordance with ASTM E-1272 and ASTM E-542. Each cylinder is individually serialized and supplied with a Corning Certificate of Identification and Capacity, traceable to NIST standards. Useful as a mixing cylinder. Graduation markings are in durable white enamel. Each features a PYREX No. 32 Standard Taper stopper. For replacement PYREX Standard Taper stoppers, see No. 7650-32.