Premium Pro Series Dual Gauge Co2 Beer Regulator Chrome Co2 Regulator - Dual Gauge Heavy duty construction, Big body for less pressure fluctuation Large adjustment knob with lock ring, adjust by hand (no tool required!). The shut-off valves are ball type check valves that prevent beer back-up into the regulator. permanent seal at the inlet nipple provides enhanced protection of leaks, eliminates the need for fiber washers upon refill.