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.
MK 4 regulators come with a Duo Tight fitting. For a barbed fitting you will want to add a swivel connector.
You will need a regulator wrench to tighten the inlet coupling to your gas cylinder.