It releases carbon dioxide and can be used in the fermentation of honey, white wine, and dairy alcohol, while helping to prevent oxidation. [Good Tightness] The excellent airtight seal of the fermentation airlock supports efficient fermentation by effectively isolating the interior environment and preventing oxidation. Automatically vents at room temperature without requiring manual control. [Easy to Put On and Take Off] This dust cap features a textured surface for a secure grip and resists slipping during use. It includes three internal buckles—gently press down to secure, release with a push-button action, then pull up and twist to open. The lid does not require drilling, as a built-in gap allows gas to escape safely. [Reusable and Versatile] These airlocks are durable and reusable, designed for long-term use. Simply clean with a disinfectant between uses. Suitable for a wide range of fermentation applications including food preservation, beer, wine, sauerkraut, kimchi, cider, fruit wine, rice wine, broccoli, carrots, ginger, kombucha, and home brewing projects. Ideal for pure fermentation processes such as white grape must, mead fermentation, and red wine secondary fermentation. Color: Transparent + Red + Black Material: PP Size: 17 cm Package Contents: 6 x Airlocks 12 x Sealing Rings Note: Light reflection and differences in display screens may cause slight variations between the color shown in the image and the actual product. Measurement may vary by +/- 1-3 cm.