The contents of this package includes 3 dozen regular mouth size TATTLER Reusable Canning Lids with rubber rings. TATTLER Reusable Canning Lids are the only known source of BPA Free, Reusable Canning Lids available. They are indefinitely reusable, made in the USA and family owned since 1976. TATTLER Reusable Canning Lids are made using FDA and USDA approved materials and are perfectly suited to replace traditional metal canning lids when using USDA recommended canning methods such as water bath and pressure canning. They are perfect for high acid foods as they will not corrode like traditional lids.