The clear glass mayo / economy jars are available with 70G silver metal plastisol-lined caps. To create an airtight seal, the container and product must be heated to recommended temperatures, softening the liner. The plastisol liner solidifies as the container cools, which creates a hermetic seal. When the container is opened, the tamper evident button on the cap will pop up indicating that the vacuum seal has been broken.
Jar Size Comparison Info