- FITS REGULAR MOUTH LIDS: This set includes 10 reusable platinum silicone seals specifically designed for regular mouth mason jars with a 2 3/8" internal diameter. Each seal measures 70mm (2.75") outside diameter, 50mm (2") inside diameter, and is 2.6mm (0.1") thick for a perfect fit. - SUPERIOR QUALITY: Our silicone seals ensure a leak-proof and airtight environment for your food storage needs. With a better design than competing products, these seals work well with ball plastic storage caps, stainless steel lids, and other types of lids. Featuring a thicker construction with a specially designed groove that faces upward for a secure fit. - THE SAFEST OPTION: Made from BPA-free, platinum cured silicone rubber, our seals are safe for use in dishwashers, freezers, and microwaves. The silicone material is non-toxic and eco-friendly, designed for food storage without leaching harmful chemicals. Platinum cured silicone offers higher purity than peroxide cured options. - VERSATILE APPLICATIONS: Ideal for storing food and beverages in the fridge or freezer, pantry organization, and even homemade fermenting lids. For optimal performance, use with threaded closure jars; however, please note that they may not produce an airtight seal with wire bail or wire clamp jars. Not suitable for canning applications. These attributes ensure you get a durable, reliable product that enhances your food storage experience, making it easier and safer to keep your items fresh.