The manifolds covered by this description are designed to allow equal numbers of cylinders to be manifold together to give an operating bank and a reserve bank. The manifold will deliver gas from the operating bank to the manifold pressure regulator until the cylinders are exhausted. At that point the supply will switch to the reserve bank and the exhausted bank can be replenished.The object is to give uninterrupted gas supply. Gas Alarm C44 is standard accessory. The Gas alarm C44 gives visual and audible indication. It surveilles and sounds the alarm when the following happens: Change operation side Leakage on reserve side High operation pressure Low operation pressure The Gas alarm C44 is able to communicate with other equipment through relays. The alarm has a battery back-up for 30 minutes of operation.