A complete one-way oronasal mask system, solid venturi operating with a single source of oxygen, “virtual” peep valve, from 3 to 15 cm H2O. pressure gauge for PEEP measurement. FiO2 adjustable between 50% and 60%. Option to operate the misting system HAR-NEB, accessory separately, without the usage of an additional source of oxygen. MDI portal. Protection filter for both patients and operators.