Heres A DOZEN handy #7 carboy bungs for homebrew wine and beer fermenters. After fermentation is complete you use these rubber bungs to completely seal off your standard GLASS 3, 5, or 6 gallon carboy until you are ready to bottle. Bungs it up much tighter than any other stopper. The #7 size is a little large on purpose, for use if your #6.5 bungs sometimes fall down inside the carboy. They ride a little high but you will be able to bung tightly without them falling inside the carboy. For drilled airlock stoppers, see our other listings.