The present invention relates to patient interface, comprising a patient interface (12 112) for delivering a gas to a user arranged to be tightened towards the users face, and at least one tightening indicator (48 148) for indicating an optimum tightening position of the patient interface (12 112), wherein the at least one tightening indicator (48 148) is arranged at the patient interface (12 112) and configured to indicate the optimum 5 tightening position at a predetermined position of the patient interface with respect to the users face.
