Feature:1. Made of high quality sandstone material, sturdy, durable and long service life.2. Good air dispersion and filter, creates bubbles in fish tank while attached to an air pump.3. It keeps your fish healthy and adds beauty to your aquarium.4. Increase oxygen levels, reduces carbon dioxide emissions, important instrument to successfully keep fish for respiration process.5. Can be widely used in a variety of places, perfect accessories for aquarium.Specification:Condition: 100 percent Brand NewItem Type: Bubble StoneMaterial: SandstoneColor: BlueSuitable for: Aquarium, Fish TankQuantity: 20PCSWeight: Approx. 145gSingle Length: Approx. 3.9cm or 1.54inchUsage Instructions:1. Connect the bubble stone with the supporting hose and connect the oxygen pump at the other end of the air pipe.2. Soak this product in water for 15 minutes before use3. Long time using, such as dirt blocking, bubble reduction, can be taken out to clean repeated use.Widely Used:1. Sewage treatment plant aeration oxygen and as a stir to prevent large particles of sediment deposition, and can remove part of the organic matter2. Fish pond(aquafarm) add oxygen to nutrient-rich water body in the environment and oxygenation in biological culture3. Live fish and seafood are transported oxygenated4. Aquarium (purifier) purification, filtration and water quality ozone sterilization and oxygenation5. Other processes that require diffused air.Package List:20 x Bubble Stone