The end fitting (6) has a connection unit i.e. pipe (6-5), connected to an oxygen supplying unit (10), and exhaled carbon dioxide sampling units (6-6) for sampling carbon dioxide exhaled by a patient. A cylindrical barrel is supported against walls of a collar (4-2) of a flexible body (4) of a mask (2). An interior separation part separates one of the sampling units and an oxygen supply chamber. The interior separation part is arranged opposite to the barrel in a direction of an interior volume (V) of the body. An independent claim is also included for a respiratory monitoring assembly comprising a determination unit for determining respiratory parameter of a patient.
