This bromobutyl rubber closure provides a gas-tight seal for all GL 25 and GL 45 laboratory bottles with sizes from 10 to 20000 ml.

• Elastic material for reliable self-sealing after needle piercing
• Upper surface features seven numbered hemispherical impressions for needle piercing
• Resistant to temperature from –50 to +121 °C

Suitable for storing oxygen-sensitive materials, cultivation of anaerobic microorganisms (pressure resistent bottles recommended), aerobic methane oxidation (MOx) studies, storage of anaerobic culture media (amber glass bottles recommended), applications requiring gas purging or sample transfer through syringes.