Fermentation Bubbler Set: The fermentation tool you will get includes 3 Plastic Fermentation Bubbler with Lids and 3 Rubber Stoppers. Enough to meet your needs and allow you to use it freely. . High Quality Materials: Our Airlock Fermentation Devices and Rubber Stoppers are made from food grade silica gel and high quality plastics, which are safe and non-toxic, and are of good tools for food fermentation. . One way valve design: Fermentation bung the one-way valve is designed to isolate air well during secondary fermentation to prevent oxidation, and make the whole fermentation process happen automatically and discharge at room temperature without manual control. . Easy to use: just install the rubber stopper with holes on the top of the fermentation container, insert the fermentation bubbler device into the rubber stopper, then pour water in the bubbler device for fermentation and close the lid to start the fermentation of red wine. . Wide Application: This Fermentation Bubbler device has a wide range of applications. It is an ideal choice for preserving food, fermenting cabbage, kimchi, sauerkraut and brewing wine, beer, mead, etc. .