The MK4 Dual Gauge gas regulator (Type 30 for CO2 / Post Mix Gas) is the only regulator you'll ever need to buy. With a large body and precision diaphragm, this regulator provides high flow rates and very accurate adjustments in both psi and kpa.
This regulator can be used for a wide range of gasses but for other gas types a different Nut and Stem Is required. Out of the box this regulator will be suitable for Carbon Dioxide (CO2 and CO2+Nitrogen Mixed Gasses). However if you want to purchase this regulator for other gas types you can interchange the nut and stem with either a Type 10 or Type 50 as as shown below:
Type 10 Nut & Stem : Helium, Argon, Oxygen
Type 50 Nut & Stem : Nitrogen