Spasciani Respirators type RC are compressed air line breathing apparatus provided with demand valve and full face mask. The compressed air in the RC respirators is supplied by a Mobile High Pressure Air Supply System (MHPASS). The MK2 warning system at the mask, advises directly the users of the imminent exhaustion of the air reserve. The RC are designed for use in polluted areas for long duration maintenance works to chemical plants and generally wherever there is or may be oxygen deficiency. These apparatuses are suitable for long duration interventions where the encumbrance of SCBA’s cylinders do not allow access or movement. They can feed two men at a time up to 50m from cylinders and allow entering awkward places. The RC system can be backed up with the BUSS system (Back Up Supply System) to be able to work in particularly dangerous surrounding. The RC respirator can feed one or two men depending on the auxiliary outfit chosen. The MK2 warning system at the mask advises directly the users of the imminent air exhaustion avoiding the need of an external attendant. However, a special device, placed by the cylinder, repeat the warning to catch the assistant’s attention.