A. It can release carbon dioxide, and can be used for the fermentation of white wine, dairy products, alcohol, etc., and can also help prevent oxidation. B. [Good airtightness] - The relatively good airtightness of the fermentation air valve is helpful for fermentation, effectively isolating air and helping prevent oxidation. C. [Automatic exhaust at room temperature without manual control] D. [Easy to install and use] - This dust - cap has a special design on its surface and is less likely to slip off when opened. - There are 3 buckles inside. Just press it down gently, and it can be installed easily; pull it up and rotate it to open. - There is no need to drill holes in the lid because there is a gap for the gas to escape. E. [Reusable and widely used] - These air valves are sturdy and can be reused. - They can be used for a relatively long time. - Just put them in a disinfectant, and they can be used again. - The air valves can be used in various fermentation projects to preserve food, such as beer, wine, sauerkraut, cider, fruit wine, rice wine, broccoli, carrots, ginger, etc. - Applicable occasions (Kombucha, wine, etc.). - Suitable for certain types of pure fermentation, such as white grape fermentation, mead fermentation, secondary fermentation of red wine, etc. F. Color: Transparent + Red + Black G. Material: Polypropylene (PP) H. Size: Approximately 17 cm I. Package contents: 6 air valves, 12 sealing rings - Only the above - mentioned package contents are included, and other items are not included. J. Note: Light reflection and different displays may cause the color of the item to vary slightly from the actual situation. K. Measurement allowable error is around +/- 1 - 3 cm.