The jalousie for the control of the air flow through the engine cooler of a vehicle has rotatable fins (2), which are supported on one side in an outer housing ring (47) provided for the connection with the engine cooler of the vehicle and on the other side in an inner supporting ring (4). The swivelling of the fins (2) occurs with an adjusting ring (45), whose engaging portions (46) work together with counter-engaging portions (10) provided at the fin ends. The adjusting ring (45) with its engaging portions (46) and the counter-engaging portions (10) of the fins (2) are enclosed together on all sides in a hollow space (49) circumferentially extending around along the adjusting ring (13, 45) for the protection against contaminants and consequently for its safe function, which is limited by two profile rings (47, 50) interlocking with each other all around.