Without these wide-mouth silicone gaskets, your wide-mouth mason jars do not have an airtight and leakproof seal and can only be so effective for your storage needs. With an airtight and leakproof seal, you can now use your wide-mouth mason jars to safely store leftover food, leftover drinks, grains, coffee beans, rice, and so much more without worrying about spoilage from the open air, leakage, or any unwanted contaminants. Plus, these gaskets are all made with high quality food-grade silicone.