quality, eco-friendly, non-toxic, harmless, bacteria-free and safe to use. The principle of a simply sealed valve is used, which makes it possible to effectively cut off the oxidizing effect of the outside air on the fermentation medium. Special design: The fermentation tube has 3 vertical chambers connected by a trap that can significantly prevent oxygen from entering your brew machine, causing the brew machine to produce alcohol instead of vinegar. Easy to use: Simply pour water through the outlet valve, place it in the brew tank lid or the rubber stopper on top of the fermentation tank, and close the lid. The whole fermentation process is automatic fermentation without manual control and can be used for a long time. Safe and hygienic: This integrated airlock fermentation tube with lid made of food-grade and alcohol-resistant plastic is essential for hygienic fermentation. You can effectively prevent flies from entering the wine/beer barrel, protect the liquid fermentation environment, and make it cleaner and more hygienic. Multifunctional fermentation tubes: The package contains 3 one-piece fermentation tubes. The fermentation attachment can be used for canning, wine brewing, beer brewing, sauerkraut and kimchi fermentation to meet your daily fermentation needs. Product Name: Plastic Exhaust Valve. Product material: plastic Product size: length 17cm, width 5cm, bottom diameter 10mm. White color Quantity delivered: 3 pieces