Directions/Specifications
Tightening the air stone will make bubbles more fine. This, in general, causes better lift for sponge filters and better oxygenation of the water. However, this can use up more of your air pumps bandwidth as it's putting more restriction on it.
Comes with 3 replacement disks if the original disks become dirty. Or you can add extra felt disks if you're pushing an abnormal amount of air through 1 air stone. You will need to tighten them quite a bit to fit them all on and it will be very fine bubbles, not recommended in normal operations.