Corning Pyrex 50mL Class A graduated cylinders are double-metric calibrated ""To Deliver” (TD) in accordance with ASTM E-1272 and ASTM E-542. The double scale, numbered both up and down, is in durable blue enamel. Height: approximately 225mm. Outer Diameter: approximately 24mm. Graduation interval: 1mL. Tolerance +/-: 0.25mL. Not sterile. Reusable. Borosilicate Glass Code 7740. Pourout top. No stopper. Cylinders are supplied with shock absorbing polyethylene bumper guards. For replacement bumper guards, see No. 3066. Corning #: 3026-50.