Used brewed beer carbonization. The 0 Micrometre stone is optimal to stress carbonate your kegged beer, or as an aeration stone prior to fermentation. Colour: silver Material: stainless-steel Size: about 48*7*12mm Package Contents: 1 x zero Micrometre Oxygenation Stone Only the above equipment content, other merchandise aren't included. Note: Light and varied reveals can cause the color of the object in the photo somewhat different from the real thing. The size allowed error is +/- 1-3cm.