DERNORD 1.5" Tri-Clamp Carbonation Stone is a brite beer fermentation tank accessory and designed to be mounted via a Tri-Clamp fitting, these stones have a submersible porous body that diffuses CO2 gas directly into brewing liquid. It is made of healthy food grade material,food Grade 2 Micron Stainless Steel SS316L Diffusion Stone with 304 Stainless Steel 1/4" female thread, High Qulity and Anti-Corrosion.With 2 micron diffusion stone will produce smaller & finer bubbles which can make the O2 or CO2 combine with liquid faster. Let your draft beer, soda, coffee and other drinks more delicate, more exquisite and more fresh. It is best choice for Oxygenation and Carbonation, for Beer, Soda, or Coffee.