Description: High Quality Materials: Our fish tank CO2 diffuser is made of clear acrylic material, which is strong and durable, has no effect on water quality and fish, and can be used with confidence. Transparent: This Carbon Dioxide Refiner makes easily observe the output of carbon dioxide, which is convenient, practical and beautiful. CO2 Diffuser Refiner: Our fish tank CO2 diffuser has good air output, high dissolution rate and is more practical. Upgraded Refinement Disc: Thinner refinement disc, higher density, increased diffusion area, better refinement effect. Improve the bottom air intake: the bottom air intake is changed to the side air intake, and the flat bottom design is more harmonious and beautiful as a whole. Specification: Material: Acrylic Size Chart: S - Refinement Disc size: 15mm, Applicable fish tank size: 30-60cm/11.81-23.62inch M - Refinement Disc size: 19mm, Applicable fish tank size: 45-90cm/17.72-35.43inch L - Refinement Disc size: 24mm, Applicable fish tank size: 60-150cm/23.62-59.06inch Package Includes: 1 Piece Fish Tank CO2 Diffuser Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful online shopping!