The Fluval Pressurized CO2 Kit is perfect for all live planted aquariums to help supply the necessary amount of carbon needed to achieve attractive, thriving aquatic plants. It contains a regulator valve to control the CO2 output, disposable CO2 output, disposable cylinder, bracket to hold the cylinder securely on the side of the tank, diffuser to dissolve the CO2 into the water and hose to attach the bubble counter to the diffuser and regulator. Quick and easy to install and maintain.