Bakelite made
These were popular on modern pop bottles in UK up until the 1980s they have a rubber ring on them to sel the liquid, the pop bottle from Banchory in North of Scotland had them in stone Ginger Beers and they had a valve in centre of the stoppers they were made of bakelite
These were popular on modern pop bottles in UK up until the 1980s they have a rubber ring on them to sel the liquid, the pop bottle from Banchory in North of Scotland had them in stone Ginger Beers and they had a valve in centre of the stoppers they were made of bakelite