A carbonation or aeration diffusion stone, either 0.5 or 2.0 micron. This can be used as a way to aerate your wort prior to fermentation, or to speed up carbonation of the finished beer. The barb fits 1/4" (6.35mm) ID tubing.
If you're looking for diffusion stones with MFL thread, you'll find them here.
From: Kegland
