It releases carbon dioxide and is used in the fermentation of honey, white wine, and dairy-based alcoholic beverages while helping to prevent oxidation. [Good Airtightness] The fermentation airlock provides excellent sealing performance, facilitating fermentation by effectively isolating the interior from external air and preventing oxidation. Automatically vents at room temperature without requiring manual control. [Easy to Put On and Remove] This dust cap features a textured surface for a non-slip grip when opening. It includes three internal bucklesgently press downward to secure 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 various fermentation applications including beer, wine, sauerkraut, kimchi, cider, fruit wine, rice wine, vegetables such as broccoli and carrots, ginger, kombucha, and other home brewing projects. Ideal for pure fermentation processes such as white grape juice, mead, and red wine secondary fermentation. Color: Transparent + Red + Black. Material: PP. Size: 17 cm. Package Contents: 6 x Airlocks, 12 x Sealing Rings. Only the listed items are included; other products are not part of this package. Note: Due to lighting reflections and differences in display screens, the item color may vary slightly from what is shown in images. Measurement may vary by +/- 1-3 cm.