Borosilicate 3.3 glass, class AS.

• High chemical and thermal resistance
• Schellbach stripe for accurate meniscus reading
• Stopcock with PTFE needle valve
• High contrast blue enamel graduations
• Batch certificate included

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. After use the joint grease must be removed as the burette tip could become contaminated. This step is not necessary when working with burettes with a PTFE needle valve stopcock.