Bolt element having a shaft part which is designed at a first end for a rivet connection to a panel element, in particular to a sheet metal part, is characterized in that the shaft part has a spherical formation at its other end the ball diameter of which is larger than that of the shaft part. This is remarkable in the conventional digital electrophotographic apparatus, since the drive signal to drive a laser or a light emitting diode for exposing the photosensitive body becomes higher in frequency as a resolution and speed are increased and tends to generate the electric noise. The device may respond with indications of the requested network connection information.