Food-grade plastic: The fermentation bubbler is made of high-quality PP plastic, which is environmentally friendly, non-toxic, harmless, bacteria-free and safe to use. The principle of simple sealing valve is adopted to effectively cut off the oxidation effect of the outside air on the fermentation medium. Special Design: The fermentation tube has 2 vertical chambers connected by a trap, which can significantly prevent oxygen from entering your brewing machine, making the brewing machine produce alcohol instead of vinegar. EASY TO USE: Just pour water into the outlet valve, put it into the brewing tank lid or the rubber stopper on top of the fermenter, and close the lid. The whole fermentation process is automatic fermentation without manual control, which can be used for a long time. Safe and Hygienic: This built-in airlock fermentation tube with a food-safe and alcohol-resistant plastic cover is a must-have for hygiene. It can effectively prevent flies from entering the wine/beer barrel, protect the liquid fermentation environment, and be cleaner and hygienic. Multifunctional fermentation tube: The package contains 2 integrated fermentation tubes. Fermentation accessories can be used for canning, brewing, beer brewing, sauerkraut, pickle fermentation to meet your daily fermentation needs.