XCR-4P-G, Four Place CGA-540 Regulator with Gauge
CGA-540 port for oxygen cylinder and 4 female CPC ports
Includes 1 extra o-ring and 5 feet (1.52 m) of red 4 mm O.D. tubing
Note: All Mountain High oxygen systems that include a cylinder also include a valve with gauge.  They do not require a regulator with a gauge.  However, a gauged regulator is a nice option when using a cylinder that does not have a gauge.