Product descriptionSize: 4.5mmColor: red, blackmaterial: plasticPackage content: 10pcs one-way valve to stop water1.Improve CO2 Dissolution: Double seal ring improves CO2 dissolution efficiency.2.Non Slip: The suction cup makes the bubble stone firmly adhere to the water tank, not easy to slip.3.Applicable For: Suitable for families, office fish tanks, ponds, aquariums.4.Replaceable Disc Oxygen Bubbler: The material is sturdy and durable. It can be used for a long time and has better dissolved oxygen effect. When the bubble burst into the water, the sound is super quiet.5.Produce Bubbles: A large number of thin bubbles are generated in the fish tank and dazzle.