Patient interface and aspects thereof

A nasal seal configured to be removably coupled to a frame of a patient interface, the nasal seal comprising:

• a seal body formed of a soft flexible material and defining an inner cavity and one or more delivery openings for supply of breathing gases from the inner cavity to a patient;
• wherein the seal body comprises a central portion and a side portion extending from each end of the central portion, the seal body further comprising an interior side and an exterior side, wherein a central interior portion of the interior side within the central portion is configured to extend across a base of a user's nose and a side interior portion of the interior side within each of the side portions is configured to extend across a side of the user's nose, wherein the interior side of the seal body is supple and configured to conform under internal pressure to surfaces of the user's nose, including, at the side interior portions of the seal body, to outside surfaces of sides of the user's nose, wherein each of the side portions defines a transition portion between the exterior side and the interior side, wherein the exterior side of each of the side portions comprises stiffened regions that are stiffer or much stiffer than the supple interior side, the stiffened regions extending to or substantially to the transition portions, wherein rearmost and lowermost sections of the side portions flare outwardly relative to adjacent portions of the seal body, and wherein the stiffened regions extend at least partially into the outwardly flared rearmost and lowermost sections of the side portions.