Features: 1.Made of high quality stainless steel material, sturdy and durable, the diffuser is not easy to remove. 2.Exquisite craft, smooth and bright surface to provide a beautiful appearance for fish tank. 3.U?shaped design, easy to install and use to save much space. 4.Good effect, with the scientific design, the diffuser has the high and best CO2 dissolve rate. 5.There are several specifications for option, you can choose the suitable one according to your demands. Specification: Item Type: Fish Tank Refiner Material: 304 Stainless Steel Color: As Pictures Shown External Diameter: Approx. 32mm/1.26inch Hole Diameter: Approx. 19mm/0.75inch Optional Length: Approx. 7cm/2.76inch, 25cm/9.84inch, 30cm/11.81inch, 35cm/13.78inch, 40cm/15.75inch PackageList: 1 x Stainless Steel Aquarium Refiner1 x Hose2 x Suction Cup Note： Note: 1. this product cannot be used in salt water tank 2. Using Instructions: Tighten when installing the refiner. Use of the new atomization will produce a large bubble, 24 hours after the disappearance 3. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.