Bored Demijohn Corks (pack of 3) are natural corks pre-drilled to accept a standard airlock, sized to fit 1-gallon glass demijohns. The bored hole lets CO2 escape safely during fermentation while keeping contaminants out.
Pair with a Handy Airlock or Bubbler Airlock. For the unbored version (used once fermentation is complete), see Plain Demijohn Corks. Sterilise with Young's Steriliser before use.