Description The of the air stone is to gradually diffuse air into the tank to provide oxygen for fish to breathe. The aquarium gas stone size is moderate, can produce a large number of stable small bubbles, can enough oxygen to your fish, but also can make your aquarium more beautiful. Feature- Color: Blue- Material: Mineral Stone.- Size: Approx. 4. 8X1. 5X1. 5cm- Made from mineral materials, effectively creating water flows and dazzling underwater scenes.- Bubbles are created in the tank when connected to an air pump.- oxygen to keep healthy and fish happy.- Easy to drive air pump, suitable for aquarium, aquarium, hydroponic.- Great choice for your fish tank. Package Including 20 x pumps