Features: 1.LOW SOUND: Aquarium bubble diffuser has double the oxygen dissolution rate and can quietly create very dense clouds of small bubbles. When the bubbles break into the water, the sound is much less. 2.SCOPE OF APPLICATION: Fish tank bubble diffuser creates many fine bubbles in the tank to make a dazzling curtain effect. Perfect for home, office fish tanks, aquariums and hydroponic nutrient tanks. 3.INCREASE OXYGEN LEVELS: Aquarium bubble stone diffuser is perfect for adding oxygen to your aquaponic growth system, increasing oxygen levels, reducing CO2 and increasing PH. 4.MANUALLY ADJUSTABLE AIR PUMP: The airflow of the fish tanks CO2 diffusers can be adjusted with a control valve. If you need a very dense cloud of small bubbles, the air pump can be manually adjusted. 5.EASY TO USE: Fish tank oxygen refiner is easy to use with 2 suction cups to keep the air stones firmly attached to the tank. Firmly fixed and not easy to slip off. Durable and not easily damaged. Specification: Item Type: Aquarium Bubble Diffuser Material: ABS Air Tray Diameter: Approx. 35mm/1.4in Total Height Of Suction Cup: Approx. 72mm/2.8in PackageList: 1 xFishTankOxygenRefiner 1 x Control Valve 2 x Suction Cup Note： Please allow some error due to manual measurement.