Universal Rubber Stopper #6 - #7 - Drilled with Airlock HoleThe #6 #7 Universal Rubber Stopper is a versatile closure designed to fit a variety of small mouth carboys, jugs, and flasks. Made from high quality, food grade rubber, it provides a 100% airtight and liquid tight seal. This model features a pre drilled center hole, specifically sized to accommodate standard twin bubble or 3 piece airlocks. Its unique dual taper design ensures a snug fit for both #6 and #7 neck sizes, protecting your beverage from