1 X Drilled Rubber Stopper #7 (Set of 3) Go to amazon.com Related posts The 16 best carboy stopper Top recommendation for carboy bung Top 10 recommendation carboy cork FeatureDrilled to accept airlock or tubing#7 rubber stopperFor 3, 5 and 6 gallon Carboys DescriptionThis is a drilled tapered rubber bung for a better seal and holds the airlock securely in place.