The gas supply consists of a 5 litre cylinder of 300 bar filling pressure. The cylinder valve and end fittings are the only metallic parts of the construction which gives the cylinder a low magnetic signature. The cylinder's composite construction permits movement in the earth's magnetic field without an induced magnetic field arising which can be detected by magnetic sensitive objects. The cylinder hand wheel can be changed for different gas mixtures (black, green, red, blue and brown), which allows for the visual identification of the gas mixture.

The cylinder is connected to a high pressure hose connection where the pressure gauge and reserve gas valve are fitted.

The gas supply must always contain a safety pressure in the cylinder, of at least 2 bar (0.2 MPa), to prevent moisture from entering through the valve into the cylinder.