The two pressure gauges indicating cylinder pressure and output working pressure, easy to read the setting The high quality bubble counter allows you to see the amount of gas being injected into the tank by counting bubbles per minute, so you can adjust the bubble rate as desired to create good growth conditions for your aquarium plants Adjust the high-precision needle valve to control the amount of CO2 entering your aquarium, ideal for use in planted aquariums or any other applications that require precise CO2 control Each kit contains a regulator, a bubble counter, a solenoid valve, a spanner and an O-ring. Industry standard nut, compatible with DIN 477 or BS 341 No. 8 or W21.8-14 (covers UK and Europe) It will take a few minutes to release the gas trapped inside it when the solenoid is powered off. If you have any questions about this item, please feel free to contact us, we are always here to assist you. Product Description Dual Gauge Pressure Indicators Dual pressure gauges help you check the working and bottle pressure simultaneously. Cylinder Pressure Gauge: 0-25 Mpa or 0-3500 psi Outlet Pressure Gauge: 0-1 Mpa or 0-150 psi Fine Adjustment The high-precision needle valve is quite sensitive, so only small movements are needed to alter the rate of CO2, which can help you achieve the best regulation of the number of bubbles per minute. Easy Setup Premium CO2 regulator comes with a wrench for easy installation. Interface: W21.8 Power Adapter: 12V Comes with a 12V power adapter for safe and stable working performance. Read more Top tips: Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.