A replaceable nasal pillow (46) for use in a patient interface device (10), the nasal pillow comprising: a base portion (62), a casing (64), and a fill material (66). The base portion is structured to be disposed on a portion of the patient interface device. The casing is coupled to the base in a manner that defines a sealed cavity therein. The casing includes an inner portion (67) and an outer portion (65) that is structured to sealingly engage a nare of a patient. The fill material is disposed in the sealed cavity defined by the casing and the base.
