These caps are designed to form an exceptionally tight seal. 

Phenolic Lids are made of phenol formaldehyde resin. It doesn't melt and is chemically inert. 

The PolyCone liner is made of an oil-resistant plastic, offering a superior chemical barrier that doesn’t let any gas or liquid escape. This snug fit will help prevent spills and leakage protecting the integrity of your product.

Perfect for preserving carbonation of beer or kombucha.

Recommended for: use with glass containers for oils, essential oils, fragrances, beer, kombucha and other liquids.

Not recommended for: use with plastic containers.