Quietly produce dense small bubbles: This aquarium bubble stone can quietly produce a very dense cloud of small bubbles. When bubbles burst in the water, the noise is reduced. Many small bubbles are produced in the aquarium and produce a dazzling curtain effect. Double oxygen dissolution rate: Ideal for adding oxygen to your hydroponic system. Increase oxygen content, reduce CO2 and increase PH. Easy to use: 2 With the suction cup, the air stone is firmly adsorbed on the tank. Durable, ideal for home, office, aquarium, fish tank and hydroponics. Adjustable: If you need a very dense cloud of small bubbles, please adjust the air pump by hand. The air volume of this nano aquarium can be adjusted via the control valve. Buy 1 get 4 free accessories: This fantastic aquarium stone kit contains a nano disc, a 35mm air disc, trachea, check valve, three-way, regulating valve 2 suction cups. Delivery quantity: 1 piece/gift trachea, check valve, three-way, regulating valve and two suction cups