A device including: a rotary actuator; an electronic pixel matrix display comprising a transparent outer layer; wherein the rotary actuator comprises an actuating part and a detector configured to detect rotational position, wherein the actuating part is rotationally mounted by a bearing so that it can rotate about an axis of rotation along a rotation direction, and the rotary actuator is arranged on the transparent layer; and wherein the rotary actuator also comprises a light guide designed to guide light of several pixels of the pixel matrix display from a light inlet surface of the light guide to a light outlet surface of the light guide either in the direction of or into an illumination surface of at least one of the rotary actuator and the actuating part.