The Aqua-Mist Air Bubble Shell Aerator will produce a steady flow of bubbles and better oxygen for your fish. It attaches easily to any air pump with standard 3/16'' airline tubing (sold separately). This Bubble Shell Aerator features a beautiful design with great functionality. It can be positioned anywhere in your tank; either blend it in with surroundings or hide it under gravel. Use the Penn Plax Aqua-Mist Bubble Shell Aerator for a beautiful aquarium and healthy fish.