An assembly of devices that includes a breathing circuit and a respiratory mask designed to conduct air or oxygen (O2) enriched gases and additional gases [e.g., nitrous oxide (N2O), halogenated gases] from a ventilator to a patient during noninvasive ventilation. It includes breathing tubes, a Y-piece connector, and typically provides connections for devices that humidify, deliver medication, and monitor gas concentration or pressure within the breathing circuit. This is a single-use device.