Suction cup can be fixed in the position of the fish tankcan refine your fish tankHe is lighterBrand New and high quality.High density chip, great refinement effect.sturdy and durable.Powerful sucker to attach to the fish tank and aquarium.Surface treatment: oxidation nickel, refined cup, non-slip knurled.adjust the length freely according to the height of fish tank.Chips will have bubble accumulation in the early stage, usually disappear after 24 hours.If the chips are not easy to vent or are covered with algae for a long time, please soak or replace them with bleach.colour: SilverMaterial: Aluminium Alloysize: 62mmSucker Diameter: 24mmPU Pipe Diameter: 4mmPU Pipe Length: 200cmRefinement Cup Diameter: 24mmPackage Contents:4 x CO2 Diffuser4 x SuckerOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +\/- 1-3cm.