#6 Drilled Rubber Stopper (DRS)
The #6 Drilled Rubber Stopper (DRS) is a pure white gum laboratory stopper. The top diameter is 1 1/8", the bottom diameter is 1 1/16", and it has a 3/8" hole drilled in the center, the perfect size for a 3-piece airlock or ripple airlock.
Great for small mouth one gallon jugs.
The #6 rubber stopper is also available as a #6 solid rubber stopper.