Aquarium CO2 Diffuser 3 in 1 - The exhalation effect is good, which is beneficial to the photosynthesis of aquatic plants and helps the growth of aquatic plants. Adopts good and stable nanometer ceramic material, make the CO2 bubbles pass evenly. Invisible mini check valve, more stable performance, easy to avoid returning. Stable structure, easily avoid backflow. With suction cup, help better fixed to the fish tank.