Description Simple operation, endless DIY fun, perfect carbon dioxide generator 1 x pressure gauge; 2 x bottle cap; 1 x control valve; tube Self-protection design: prevents water from flowing back into the magnet and cylinder. The aquarium hose with backflow function prevents backflow when the pressure changes, which may damage the surface of the aquatic plant and the CO2 cylinder. Smart Meter: Used for Co2 controller. By connecting the water meter, the carbon dioxide volume can be calculated to supply enough carbon dioxide to plants. It also has a check valve function to prevent liquid from flowing back when the pressure changes. Easy to Install and Use: A great choice to make your aquarium unique. Simply and cheaply produce CO2 continuously through chemical reaction, and only need to adjust the airflow according to the volume of the CO2 valve. instruction: The standard version is a white quick screw bottle cap, and the quick insert version is a white double ear small U refiner
