The present invention relates to a member (14, 24, 26) of a patient interface (10) for providing a flow of breath-able gas to a self-ventilating patient (12). The member (14, 24, 26) includes a wear-out indicator (32) for indicating a wear-out of the member (14, 24, 26) to the patient (12). The wear-out indicator (32) includes an elastic structure (34) that appears in a first colour in an unstressed condition and is configured to re-versibly change its apparent colour when being stretched and re-turned to its unstressed condition again. The elastic structure (34) is configured to indicate a wear-out of the member (14, 24, 26) by appearing in a second colour in its unstressed condition when the structure (34) has lost at least a part of its elasticity, wherein the second colour is different from the first colour.