Feature: 1. Fine workmanship: The overall mirror surface is finely polished, which complements the aquatic plants beautifully. 2. Simple Installation: Easy to install, connect to PU pipe for use, freely adjust the length according to the height of the cylinder. 3. Easy to Disassemble: Easy to unscrew, simple to change the film, the surface is non slip knurled design. 4. High Quality Materials: Aluminum alloy material, polished surface, anti corrosion, anti rust, longer life. 5. Rugged and Durable: The sturdy aluminum structure is sealed with an o rings, which is easy to clean and maintain. Specification: Item Type: Refiner Product Material: Aluminum Alloy External Trachea: Approx.4mm/0.2in Caliber Trachea Refining Cup Diameter: Approx.2.4cm/0.9in. Package List: 1 x Refiner1 x Sucker Note: It needs to be soaked in water for 24 hours before use, the bubbles are bigger and more, the air is evenly discharged, and the effect is better.