High Quality Materials:This transparent fermentation airlock is made of food grade plastic with transparent color, which lets you know exactly when the fermentation is slow and eventually stops and it will last a lifetime with good care. Advantage:This airlock bubbler tube allows fermentation gas to escape while excluding air and contaminants. The transparent airlock lets you know exactly when the fermentation is slowing down and eventually stopping the fermentation. Easy to Use: Just pour water into the airlock, insert it into the lid of the brew reservoir or in the rubber stopper located above the fermentation vessel, then cover it. The package contains 5 pieces. Exterior:The S-shaped design, connected by a trap, prevents oxygen from entering your fermenter. The whole fermentation process is automatic fermentation, without manual control, and can be reused for a long time. Use:Not only available for pure juice fermentation, such as white grapes , meadows, fermentation of wine honey, secondary fermentation of red wine, but also ideal for drinking: all homemade drinks, beer, wine, cider and spirits.