Ball One-Piece Leak-Proof Lids feature a one-piece, screw-on design that is leak-proof, airtight, and freezer and dishwasher safe. Store your favorite recipes in iconic Ball jars and secure with Ball Leak-Proof Storage Lids. The airtight seal is perfect for herbs, spices, on-the-go salads, smoothies, and more and is freezer safe for storing jam recipes, sauces, and soups.