1、1.It is easy to clean and replace, and it is very convenient to use; 2、2.It can better refine carbon dioxide in water and maintain water plants; 3、3.Install the ceramic disk into the O-ring and inject water into the bottom cup and assemble it before use. 4、4.It is easy to clean and replacement, very convenient. 5、5.Brand new and high quality. Features: 1. It is easy to clean and replace, and it is very convenient to use; 2. It can better refine carbon dioxide in water and maintain water plants; 3. Install the ceramic disk into the O-ring and inject water into the bottom cup and assemble it before use. 4. It is easy to clean and replacement, very convenient. 5. Brand new and high quality. Specification: Condition: Brand New optional Size: approx 12mm-fine film diameter 1.2cm/0.4inch 15mm-fine film diameter 1.5cm/0.5inch 20mm-fine film diameter 2.0cm/0.7inch 26mm-thinning sheet diameter 2.6cm/1.0inch Material:Ceramic + rubber Use range: fish tank, aquarium Package List: Refined film*1 Apron*1 Note: 1. Please allow 1-3cm error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.