Abstract: An alignable sensor, the connecting housing of which receives within a passage rotatably a stub of a prismatic intermediate piece, the intermediate piece comprising a holding plate aligned at an angle of 45.degree. to the axis of the connecting piece and to a side wall, for a sensor head, and the sensor head and the intermediate piece having in common a parallelepiped contour. The passage comprises a plurality of locking recesses for fixing noses of the connecting piece. Catch curves of the stub cooperate with catch profiles of the connecting housing, in order to hold, in a catching manner, the stub in the axial direction. The holding plate rotatably receives a flange of the sensor head.