An amazing high quality bung that allows venting!

This Premium Breathable Silicone Bung has a two-piece design that allows you to use it in an open position to act as an airlock, or a closed position to act as a solid stopper allowing you to start and finish the ferment without switching out the bung. In the open position the bung allows the release of CO2 while maintaining a seal against oxygen coming in, which is ideal for alcoholic or malolactic fermentation in barrels or tanks. When fermentation is over you just push the center cap into the bung to create a solid stopper. It has built in tabs for easy removal.

Tapers from 1 7/8" to 2 1/4" diameter. Fits most 30 and 60 gallon barrels as well as the hole in the lid of most Variable Volume tanks.