<p>The air exhaust has an outlet opening (8) forming the nozzle casing with at least a lamella (9) which has a first area (11) followed by a second area (12). The detachable connection element (22) is force fit attached to the first area (11) in the transverse direction of the lamella. The transition area (16) is provided between the first and the second area which acts as the outlet.</p>