Penn-Plax Aquarium Airstone Cylinder. When added to your aquarium, it produces a steady flow of bubbles, providing a better supply of oxygen to your fish. It attaches easily to any air pump with standard 3/16" airline tubing (sold separately). The air stone can be positioned anywhere in your tank, either blend it in with surroundings or hide it under gravel.
Increases surface agitation
Accelerates oxygen replenishment
Helps release carbon dioxide buildup
Penn Plax is a manufacturer of top aquatic supplies and decor. We specialize in creating excellent pet products for animals both great and small.