This item is a fish tank accessory. It help create bubbles in fish tank while attached to an air pump. It is an important instrument to successfully keep aquatic fish for respiration process. Used to increase the dissolved O2 level in the aquarium. It will perform better if the power of the pump is stronger. Feature - Color: Dark Green - Material: Honing Stick - Size: 11.6x1.5x1.5cm/4.6x0.6x0.6inch - Rising bubbles vital aquarium aeration and water movement. - Equal distribution of air bubbles through out stones. - Made of sturdy material, it can be used for a long time. - These are nice air bubbles that are easy to install. - If the working performance is not well after a long time, you should take it out and wash it.