0.5 Micron diffusion stone used primarily in wort oxygenation, in combination with an oxygen tank and regulator. Smaller sized holes require much more pressure that air pumps to allow air to pass through the holes.
Can also be used for carbonating beer very quickly. Simply attach a length of 1/4" ID tubing from the gas side dip tube in a keg to this barb, and set your CO2 regulator to the required pressure. CO2 will dissolve directly into the beer, and reduce carbonating times dramatically.
Avoid touching the stone, as this can clog the small holes. If this occurs, boil the stone for 3-5 minutes; this should remove buildups. To sanitize before use, run the system through sanitizer for 5 or so minutes before use.
Full 316 Stainless construction. Features a 1/4" Barb.