Merck, Z512125-1PAK, Serrated natural rubber septa

General description
Closure has a turnover flange molded to grip outside of container neck, promoting a double seal in conjunction with annular serrations on a hollow plug. Annular serrations depress themselves against the inside wall of the bottle neck, making each serration a suction sealing point.
Note: For extra security when using large bore transfer needles, fasten septum to bottle or flask opening with a wrap-it tie. See ties and accessory tool listings on next page.
Application
Serrated natural rubber septa are suitable as a temporary closure for glassware joints, tubes, bottles, nuclear magnetic resonance (NMR) tubes, ampules, and cannulation techniques in air-sensitive chemistry.
Features and Benefits
Natural rubber septa are:

• made of low-density /US/ennatural rubber
• used to cover mild organic solvents and aqueous solutions