【CO2 aquarium kit】 You will receive 1 aquarium atomizer. Colour: silver. 【CO2 Diffuser Aquarium Size】Length: 6cm/2.34 (Approx). Refine Cup Diameter: 24mm. 【Material】 Made of high quality aluminum alloy. The surface is nickel plated and never rusts. High-density refined tablets make the bubbles more delicate, and it is not easy to block the diffuser. 【Unique design】More convenient than normal tube. Mount your U-tube to the rim of your aquarium in the desired location. Ideal for use with CO2 injection systems or bubblers. Thanks to the knurled design, it has good anti-slip performance and does not harm the fish and shrimp in your aquarium. 【Function】Aquarium CO2 diffuser can greatly improve CO2 solubility, high carbon dioxide diffusion efficiency. Provide a healthy environment for your fish and improve the growth and health of your plants with sufficient CO2 supply.