The bubble counter with check valve, can prevent the backflow when the pressure changes, and this can ensure the water pressure gauge and CO2 bottle from damage. East to install and use, a good choice to make your fish tank different. It can count the volume of carbon dioxide and supply the plants with enough carbon dioxide. Features: VISIBLE CO2 OUTPUT: The output of carbon dioxide can be seen clearly, so that better supply sufficient CO2 for water plants. SUITABLE FOR: G1/8 interface trim valve fits for the single head solenoid valve. If not the G1/8 interface, fits for the 4*6mm air pipe (inner diameter 4mm and outer diameter 6mm). DURABLE AND EASY TO INSTALL: Be made of aluminum alloy material, strong and sturdy. Also, easy to install and disassemble. INSTRUCTION: CO2 source-trim valve-solenoid valve- bubbler counter-air tube-bubble diffuser-fish tank, pay attention to the CO2 flow direction during installation. WITH CHECK VALVE: With non-return function to prevent the backflow
