[chickenchase-r]

the seal is waste depending what it is made of. ramune uses some kind of plasticy stuff, for example

[numpad0]

Historically it was pure glass but modern retro recreations usually adds that plastic cap, pusher rod and a plastic wrapper for easier manufacturing as well as for corporate liabilities. Those aren't technically necessary.

[chickenchase-r]

I have not seen one that is pure glass. The oldest I have seen has a gasket. Every source I see indicates a rubber gasket was used in the first versions.

[huytersd]

Ah interesting. I though it was glass on glass.