Fill the Bubbler Airlock with water and insert in drilled stopper or bung to vent gases during fermentation.
"Bubbler" style airlock makes a gratifying "bloop" noise during active fermentation. It is the preferred airlock for secondary fermentation, as it is possible to monitor the pressure inside the fermenter.
To use: Insert assembled airlock into the hole of the rubber stopper that fits your current jug or carboy. The airlock cap should always stay on top when in use; it has several small holes in it that allow gas to escape but prevent the water inside from quickly spilling out if tipped or jostled.