Used to provide a positive seal on your carboy. Drilled hole is compatible with standard airlocks.

Top Diameter: 1.048"

Bottom Diameter: 0.909"

Compatible with: older models of Big Mouth Bubbler® EVO 2 w/screw-on lid & Little Big Mouth Bubbler®

Not sure if this is the correct stopper for your purposes? Consult our stopper information table below:

Stopper Type	Compatible With:
No. 2 Drilled Stopper	Standard Beer bottles
No. 5 Drilled Stopper	Big Mouth Bubbler® EVO 2 w/screw-on lid (older EVO 2 models) & Little BMB
No. 6 Stopper Drilled or Solid	1 Gallon Jugs
No. 6.5 Stopper Drilled or Solid	Glass carboys, Big Mouth Bubbler® plastic (5 or 6.5 gallon) or EVO 2 w/ Universal Lid. Ideal fit is 6 gallon carboy.
No. 7 Drilled Stopper	5 Gallon glass carboys
No. 10 Drilled Stopper	PET Plastic Carboy 5 or 6 gallon
Small Universal Stopper - Drilled or Solid	Glass Carboys (3, 5, 6, 6.5), Big Mouth Bubbler® Plastic 5 or 6.5 gallon or EVO 2 w/ Universal Lid.
Medium Universal Stopper - Drilled or Solid	PET Plastic Carboy 5 or 6 gallon