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 kPa, Bar and PSI.Includes 8mm x FFL duotight.NOTE: This regulator is sold with the Green 65PSI (4.5 BAR) pressure relief valve.