Drilled Rubber Stopper #6.5
A drilled and tapered rubber stopper with a 9 mm center hole. The #6.5 rubber stopper fits most carboys.
When placing an airlock and rubber stopper onto a carboy, it's helpful to first fit the airlock into the rubber stopper. This causes the stopper to stretch out wider, which allows it to seat up higher in the carboy opening and prevents the rubber stopper from accidentally getting pushed into the carboy. Remember - when placing an airlock and stopper into a carboy, the goal is to produce an airtight seal. Gently pressing the stopper into the carboy mouth will produce a seal. Do not force the rubber bung into the carboy's mouth and risk pushing it through.
- Top diameter: 34 mm
- Bottom diameter: 28 mm
- Height: 25 mm