The #10.5 Solid Rubber Stopper (SRS) is a pure white gum laboratory stopper. The top diameter is 2 1/16" and the bottom diameter is 1 3/4". It is solid, with no hole drilled in it, so it is perfect for putting on a fermenter once fermentation is complete or if you are storing a clean and dry fermentor.

The #10.5 Rubber Stopper is also available as a .