Quality materials: Our airlock grommet is made of durable silicone and is resistant to high temperatures for long-term use. Good performance: This fermenter lid grommet is easy to install into the lid and provides a secure seal to protect food from oxygen. Use with airlocks to extend fermentation time. Hermetic sealing: This silicone grommet works well with airlocks to create a tight seal, preventing oxygen from entering the fermenter and helping maintain the fermentation process. 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 easy insertion. Wide use: This airlock gasket is compatible with most airlocks, plastic lids, and straws. Ideal for converting mason jars into fermentation vessels. Features: Made of durable silicone, the airlock grommet offers reliable sealing performance and fits most standard airlocks. Suitable for various fermentation applications. Easy to install and provides a secure seal when used with bucket lids. Specifications: Color: Black Material: Silicone Size: Outer diameter: 1.59 cm Package Contents: 50 x Airlock gaskets Note: Light and display differences may cause slight color variations. Measurement error allowed is +/- 1-3 cm.