Seal your carboys or demijohns with Cork Bungs with Hole. These bungs are made from high-quality cork and have a hole in the center, allowing for the insertion of an airlock. They are perfect for use during fermentation, as they prevent air and bacteria from entering the container while allowing carbon dioxide to escape. The bungs come in a pack of 10 and are suitable for use with standard carboys or demijohns. Elevate your home brewing with Cork Bungs with Hole. Cork Bungs with Hole for use with Airlocks and Demi-Johns.