For all of your fresh preserving needs, the Anchor Hocking Wide Mouth Canning Lids help create a tight seal on your wide 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 lids are compatible with all Anchor and Ball branded wide-mouth mason jars. There are 12 total mason jar lids included per order.