A patient interface for delivery of a flow of pressurised air from an air circuit to an entrance of a patient's airways, the patient interface comprising: a plenum chamber; a seal-forming structure provided to the plenum chamber; a plurality of connection ports (3600A, 3600B) configured to receive the flow of air from the air circuit and to deliver the flow of air to the entrance of the patient's airways via the seal-forming structure, the plurality of connection ports comprising a first connection port and a second connection port; and one or more positioning and stabilising structures configured to provide a force to hold the seal-forming structure in a therapeutically effective position on a patient's head in use, wherein the patient interface is structured and arranged to be worn by the patient in a first use configuration and a second use configuration, wherein in the first use configuration, the air circuit is connected to the first connection port that is positioned superior to the patient's otobasion superior and that is connected to ports on sides of the plenum chamber via a first and second gas delivery tubes being constructed and arranged to contact at least a region of the patient's head superior to the otobasion superior of the patient's head and position and stabilise the seal-forming structure of the patient interface in the therapeutically effective position, characterized in that in the second use configuration, the air circuit is connected to the second connection port that is positioned on an anterior side of the plenum chamber inferior to the patient's otobasion superior, and wherein, when the air circuit is connected to the first connection port in the first use configuration, the second connection port receives a vent structure or a stop. a plenum chamber; a seal-forming structure provided to the plenum chamber; a plurality of connection ports (3600A, 3600B) configured to receive the flow of air from the air circuit and to deliver the flow of air to the entrance of the patient's airways via the seal-forming structure, the plurality of connection ports comprising a first connection port and a second connection port; and one or more positioning and stabilising structures configured to provide a force to hold the seal-forming structure in a therapeutically effective position on a patient's head in use, wherein the patient interface is structured and arranged to be worn by the patient in a first use configuration and a second use configuration, wherein in the first use configuration, the air circuit is connected to the first connection port that is positioned superior to the patient's otobasion superior and that is connected to ports on sides of the plenum chamber via a first and second gas delivery tubes being constructed and arranged to contact at least a region of the patient's head superior to the otobasion superior of the patient's head and position and stabilise the seal-forming structure of the patient interface in the therapeutically effective position, characterized in that in the second use configuration, the air circuit is connected to the second connection port that is positioned on an anterior side of the plenum chamber inferior to the patient's otobasion superior, and wherein, when the air circuit is connected to the first connection port in the first use configuration, the second connection port receives a vent structure or a stop.