Made of BPA free sturdy glass jar, with non-slip bottom design. Two different capacity jars suitable for different need of daily life. Glass Fermenter Wide Mouth Lid jar One-Way Fermentation Kit for Pickles, Sauerkraut, Kimchi, Fermented Probiotic Foods Making your own delicious sauerkraut or kimchi is easy with our special fermentation jar Built-in sealed silicone gasket makes sure the jar is airtight. Automatic air release valve. After the gas is produced inside the jar, it will only to be discharged, and the external gas cannot enter the bottle. To maintain the taste and quality of the brewed product, Besides, airtight to keep coffee, juice and more stay fresh longer. easy to disassemble and clean.