Check the listing for details. Replacement Stainless Steel 0.5 Micron Diffusion Air Stone NSF Approved. Color: Silver, Condition: New. Listed at 7.95 USD. .5 MicronDiffusionAir Stone 0.5-micron diffusion stone Easy to useFast CO2 carbonation (3-6 hours)Nitro infusion for Nitro Brew CoffeeOxygenate during Fermentation Description This micro-perforated diffusion stone is a fantastic way to give nature a helping hand. Jump-start fermentation by getting much-needed oxygen into the wort and to your yeast fast and consistently. It’s also perfect for force carbonation of your brew.These are also great when in conjunction with a nitro or carbonating keg lid for carbonating or nitrogenating your brew much faster and easier than conventional methods. 1/4″ barb attached permanently to stone. Simply connect a regulated gas source (tank, oxygen pump with enough pressure) with 1/4″ food-safe tubing (not included) to the stone and diffuse away.Easy to clean. Just boil before your next use and it’s clean and ready to go.Dimensions: 1/2″ diameter, 1 7/8″ total length. Features High-Quality Construction Stainless Steel Barb Measurement 1/4" Dimensions1/2" diameter x 1 - 7/8" length CompatibilityOxygen, Carbon Dioxide and Nitrogen Micron0.5 Applications Homebrew, Cold Brew, Nitro Coffee, Kombucha Tea Thank you and cheers!Beverage Elements