brand new and high quality Features: With a CO2 atomizer,fish will live more freely and healthily,for professional people who are breeding fish,this CO2 diffuser will be necessary for them.CO2 diffuser will make CO2 atomize greatly and subtly.It is made from high intensity, and anodizing crafts,which will make it more rust resistance and durable.Diffuser or replacing tube can be available for you to choose. Notice: 1.When products are finished,atomizer is not tightened,you need twist it a little tight while you receive it. 2.Do not use wrench or other metals tool to install or remove it,in for case of damaging the products. 3.This atomizer adopts high density ceramic atomizing tube,and it should be soaking in water for 24-48h to reach the best atomizing effect. 4.The atomizer is installed on the outside of fish for tank,and when it is on use,it will make some noise which is normal situation,and it is not air leakage. Specification: Material: Alloy Type: CO2 diffuser Color: As pictures shown Size: Tube: 3.6x1.7cm(1.42x0.67in) 4.8x1.8cm(1.89x0.71in) Atomizer: S: 110x55mm(4.33x2.17in) For 12/16mm Hose L: 135x53mm(5.32x2.09in) For 16/22mm Hose Quantity: 1 Pc(tube or atomizer only,other accessories demo in the picture are not included!) Note:1.Please allow 1-3cm error due to manual measurement.pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 x Tube/Atomizer