A respiratory nosepiece (10) and method of manufacturing the respiratory nosepiece, the respiratory nosepiece including a first nasal prong (110) with a first channel (112) extending there through, and a first side port (130) connectable to tubes (192, 194) having different first and second diameters. The first side port has a second channel (131) extending there through and in communication with the first channel. The second channel includes a first section (134) having the first diameter, a second section (136) having the second diameter, a first step (135) between the first and second sections, and a second step (137) between the second section and an end (133) of the second channel. The first and second channels are formed during injection molding by pins (412, 422, 431, 441) having flat pin-on-pin geometry to reduce resin flash within the channels.
