All-glass stopcock for smooth motion and flow adjustment.

• Class A and Class B versions available
• Made from high quality 3.3 borosilicate glass
• Blue enamel graduations for contrast against clear liquids
• Straight single bore

These premium burettes are made of precisely bore high quality, heavy duty borosilicate 3.3 glass with excellent durability and chemical resistance. Both Class A and Class B versions conform with DIN ISO 385 standards for accuracy. Each burette includes an attached key stopcock made of high quality glass and features blue graduations and markings. To avoid material damaging friction between the burette and the stopcock and to ensure tightness joint, grease is necessary when working with burettes with glass stopcock. Calibrated to deliver.