Aquarium Control Valves Air Pump Single Way Valves Plastic Air Flow Control Regulators for Fish TankEasy to UseIt is very easy to use, just plug it into the hose and tighten the interface. It is very easy to install and can prevent water leakage.MaterialIt is made of high-quality hard plastic, very durable, non-toxic, tasteless, safe and hygienic. It can be used for a long time and will not harm the health of the fish.FeaturesIt easily adjusts the airflow, adjusts the amount of oxygen, increases or slows down the airflow into the air stone, or controls the water flow through a simple rotary knob.ApplicationIt is suitable for all aquariums and fish tank installations, and is a very practical air pump and air valve accessory.Colour: BlackSize: length 3.8CM, height 2.0CM, inner diameter 4mmDelivery Quantity: 20 PiecesWarm prompt:1.As different measuring methods,it will occur 1-3 cm deviation about the items,please ensure that it is okay for you before ordering.2. Because of different monitors and lamplight, the picture may not reflect the actual color of the item, really thank you for your kind understanding3. Only the above package contents, excluding other products.