SIMPLE TO USE - Our seal creates an airtight, leak-proof seal with any wide mouth mason jar lid. Our mason jar seals fit securely on the rim of the jar. Other seals try to cling to the inside of the lid and are prone to falling out.;REUSABLE - Made of FDA grade, BPA free, dishwasher safe silicone, these seals can be used over and over.;VERSATILE - Because our sealing rings fit on the rim of the jar and not inside the lid, they can be used with any wide mouth, screw top, mason jar lid.;DURABLE - Molded to 3/32 thick, these gaskets are built to last.;PACKAGE INCLUDES 12 SEALS - Jars and Lids are not included. NOT FOR CANNING - These seals are for storage purposes only and cannot be used for canning. Not for use with Fido, Hermes or other clamp lid jars.