Click to expand Tap to zoom Diffusion Stone 0.5 Micron by BrewGoat® Sold out €12,95 Out of stock 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Sold out Diffusion Stone 0.5 Micron with nipple 7 mm.Carbonic acid or oxygenate your beer before fermentation.