Betta Cylinder Air stones create a wall of air bubbles to decorate, aerate and improve circulation in your aquarium or pond. To install, connect to standard (4/6mm) silicone or plastic air line from the air pump and lay anywhere in the aquarium or pond. The stone can be hidden from view using rocks, plants or other decor etc. Recommended for use with Betta Airline Tubing, made from either silicone or plastic.