The MK4 Dual Gauge gas regulator (CGA-320 for CO2) 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.
NOTE: This regulator is sold with the Green 65PSI (4.5BAR) pressure relief valve. If you need the lower 35psi/(2.5BAR) or alternatively if you need the higher 100psi(6.9BAR) pressure relief valve this is also sold separately.