Quality materials: Our airlock grommet is made of durable silicone and BPA-free materials, resistant to high temperatures for long-term use. Good performance: This fermenter lid grommet is easy to install into the lid and provides a hermetic seal to protect food from oxygen. Use with airlocks to extend fermentation time. Hermetic sealing: The silicone grommet works effectively with airlocks to create a reliable seal, preventing oxygen from entering the fermenter and supporting consistent fermentation. Quantity and size: You will receive 50 airlock grommets with an outer diameter of 5/8 inches and an inner diameter of 3/8 inches. A 5/8 inch hole is required in the fermenter lid for proper installation. The grommets are easy to insert and provide a secure fit. Wide use: This airlock gasket is compatible with various types of airlocks, plastic lids, and straws. Ideal for converting mason jars into fermentation vessels. Features: Made of durable, long-lasting silicone, the airlock grommet offers excellent sealing performance and fits most standard airlocks. Suitable for use in home fermentation applications. Versatile application: The grommet is compatible with most airlock types, plastic bucket lids, and straws. Easily create custom airlock setups for fermentation. Easy installation: Simple to insert into bucket or jar lids, providing a secure and airtight seal. Specifications: Color: Black Material: Silicone Size: Outer diameter: 1.59 cm (5/8 inch), Inner diameter: 0.95 cm (3/8 inch) Package Contents: 50 x Airlock grommets Note: The package includes only the items listed above. Other accessories are not included. Lighting and monitor settings may cause slight variations in color between the image and the actual product. Measurement may vary by +/- 1-3 cm due to manual measurement.