from Beer & Wine Hobby:
Today get a Free Vented Silicone Stopper when you spend $50 or more*
Fermenting/Ventilating Bung – Fits 3, 5, 6, and 6.5 gallon glass carboys and acts as both a stopper and an airlock. Its five vents and pliable seal allow CO2 to escape but prevents entry of oxygen and airborne contaminants. No more suck-back of liquid from the airlock; great for extended fermentations where CO2 production is slight.
*Excludes Gift Cards
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