Peter's Pickle Wide Mouth Mason Jar Anaerobic Fermenting Kit (Silver) Anaerobic Fermentation - Our fermentation kit is designed to prevent oxygen from entering the bottle, while allowing the carbon dioxide (CO2) to escape. S-Airlock - Compared to 3-piece airlock, S-airlock allows for more visibility of the bubbles. This means you can better monitor the fermentation process and stop fermenting at the right time. Plus, it's more fun as you can see more bubbles. Easy-to-use - Whether you are new to the art of pickling or not, Peter's Pickle Fermentation Kit is easy to use. Simply put your favorite fruits, vegetables, or beverage in a mason jar, close the lid, and watch the magic happen. Recipe Book - Purchase our fermentation kit and receive a complementary recipe book filled with a variety of Asian-cuisine inspired pickles. Made in USA - All products in the kits are Made in USA and assembled in California.