Buon Vino Stopper Small - Solid - Fits 3, 5, 6, 6.5 gal Glass Carboys
Buon Vino stoppers have a longer taper to help produce a better fit and a snug seal, and a lip which prevents them from falling into your container. Solid with no hole.
A universal soft rubber bung that will fit both airlock styles and offers some advantages over traditional gum
#6-7 (small) size is recommended for 3-6.5 gallon glass carboys. This size is also referred to as a Universal carboy bung.