CO2 pressure regulator
The CO2 pressure reducer with manometer and fine-tuning
The CO2 regulator has 2 gauges. On one can the cylinder pressure be read to see how full the bottle still is, on the other gauge can the pressure be read. With the needle/doseerventiel this is very accurate and a precise amount of CO2 to the aquarium to be dosed. Also, the pressure regulator locked against overpressure. The CO2 pressure regulator fits almost all refillable CO2 bottles with external screw thread and has a so-called DIN 477 thread (W21,8 x 1/14, European standard).
Read here: all about adding CO2 in the aquarium