Corning Pyrex 250mL Class A graduated cylinders are double-metric calibrated ""To Deliver"" (TD) in accordance with ASTM E-1272 and ASTM E-542. The double scale is numbered both up and down in durable white enamel. Height: approximately 340mm. Outer Diameter: approximately 39mm. Graduation interval: 2mL. Tolerance +/-: 1mL. Material: Borosilicate Glass Code 7740. Reusable. Not sterile. Pourout top. No stopper. Supplied with plastic bumper guards to reduce accidental breakage (for replacement bumper guards see Cat. No. 3066). 12 Each/Case. Corning #: 3023-250.