Suction cup can be fixed in the position of the fish tank can refine your fish tank He is lighter 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: Silver Material: Aluminium Alloy size: 62mm Sucker Diameter: 24mm PU Pipe Diameter: 4mm PU Pipe Length: 200cm Refinement Cup Diameter: 24mm Package Contents: 6 x CO2 Diffuser 6 x Sucker Only the above package content, other products are not included. Note: Light reflection 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.