Package Contents: Receive a set of four colorful airlock fermentation lids designed for wide mouth jars, perfect for crafting homemade sauerkraut, , , and more. Each lid ensures a secure, airtight seal to facilitate the fermentation process. High-Quality Silicone Construction: Crafted from premium silicone, these fermentation lids are built to last. They resist wear and tear, maintaining their shape and functionality through numerous fermentation cycles without cracking or warping. Optimal Size for Wide Mouth Jars: Each lid measures approximately 8.5cm/3.35in in diameter, tailored specifically for wide mouth jars. This design guarantees a snug fit, essential for effective fermentation. Note: These lids are not suitable for regular sized jars. Advanced Self-Burping Design: Equipped with a one-way valve, our lids automatically vent excess gas during the fermentation process, eliminating the need for manual burping or messy water airlocks. Enjoy hassle-free fermentation with perfect results every time. Integrated Date Tracker: Each lid includes a date marking feature to help you monitor the and progress of your fermentation. This convenient tool simplifies tracking, ensuring your fermented goods are fresh and at their . Color: As Shown Material: Silicone Package Contents: 4*fermentation lids Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.