Fisher is one of the most popular manufacturers of automatic changeover regulators, known for the quality of their products, and this item, type R130, is no exception. The item is able to deliver an outlet pressure of up to 3.1 bar.
Apart from the presure gauge, the two other components are two Type 67C regulators, linked together. The gauge also serves as an indicator for the changeover, for easy determination of when the manifold has been automatically switched to the reserve cylinder from the supply cylinder.