Bung Size Base: 27mm. Just half fill with water and you're good to go.
Fermentation Bubbler Airlock Bored Rubber Bung Stopper for Demijohn Wine Beer
Airlock & Rubber Bung - Fermentation Bubbler Combo for Demijohn Fermenter
Airlock & Rubber Bung x 2 - Fermentation Bubbler Combo for Demijohn Fermenter
4x Glass Bubbler Airlock For Wine Beer Cider Making Mash Fermentation Lock New
2x Glass Bubbler Airlock For Wine Beer Cider Making Mash Fermentation Lock NEW
2-Chamber Bubbler Airlock, Home Brew Beer Wine Fermentation Air Lock Set 4 Packs
