The first stage typically has at least one outlet port delivering breathing gas at full tank pressure which is connected to the diver's submersible pressure gauge or dive computer, to show how much breathing gas remains in the cylinder.
The first stage typically has at least one outlet port. This at least one outlet port is delivering breathing gas at full tank pressure. This full tank pressure is connected to the diver's submersible pressure gauge or dive computer. This was to show how much breathing gas remains in the cylinder.