For all of your fresh preserving needs, the Anchor Hocking Regular Mouth Canning Lids help create a tight seal on your regular mouth canning jars. When heated during the canning process, the soft, BPA-free sealing material on the underside of lid seals in freshness and prevents oxygen and bacteria from entering the jar. If properly applied, the initial seal will maintain food quality for over a year. The order comes with 12 mason jar lids for bulk use. Lids are compatible with all Anchor and Ball branded regular mason jars.