A patient interface includes a plenum chamber pressurisable to a therapeutic pressure, a seal-forming structure to maintain the therapeutic pressure in the plenum chamber, and a positioning and stabilising structure (PSS) to provide a force to hold a seal-forming structure on a patient's head. The PSS has at least one arm to be positioned adjacent to a cheek of the patient, and a strap removably received around the arm to contact a posterior region of the patient's head. The strap has a first coupling having a mechanical connector to engage the arm and limit movement of the arm into and out of the cavity, a second coupling spaced apart from an outer surface of the first coupling, and a sleeve being folded over the second coupling and positioned between the first and second couplings.