A fluid coupling conduit is for a patient interface device. The fluid coupling conduit includes a body including: an inlet end structured to receive a flow of breathing gas, an outlet end fluidly coupled to the inlet end, and a middle portion disposed between the inlet end and the outlet end, the middle portion including a rim defining a relief aperture provided in an aperture plane. The fluid coupling conduit further includes a blocking member substantially disposed in the relief aperture, a number of openings being formed between the blocking member and the rim. The rim includes a number of protrusions extending transversely to the aperture plane.
