Classic, sturdy, simple, one piece “S” design. Airlocks are also called Fermentation Locks. Airlock stem will fit inside the hole of any drilled stopper (not Included)
Airlocks are an integral part of a closed fermentation set-up, filled with water or vodka, they keep bugs, dust and bacteria in the air away from fermenting beer or wine. A tight sealing lid and a drilled rubber stopper are needed to complete the closed fermentation set-up.