The Bubbler with a red cap from Youngs is made from plastic and is the perfect solution for having an airlock on your fermentation barrel. Half fill with water and when fitted protects the ferment by allowing a visual passing of gas pressure to escape but admits no air. This is an ideal tool to have within the homebrewing process. Bubbler Features Youngs Bubbler, Plastic with Red Cap / 5285 Airlocks fermentation barrels Gass pressure still escapes but no air Half fill with water Youngs\' Ref. MPN: 5285Colour: ClearSizes: One SizePM Ref: 414186