Borosilicate 3.3 glass, class AS.

• High chemical and thermal resistance
• Schellbach stripe for accurate meniscus reading
• Stopcock with PTFE key
• 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 that have a 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 key stopcock.