A reflection plate is formed so as to have a wavy surface, and to have uneven distribution of normal line directions of the surface in terms of a specific azimuth angle. A sensor arrangement is at least partially integrated into the spark plug but disposed outside the light guide device, and is embodied for the acquisition of operating data of the spark plug andor of a combustion chamber associated with the spark plug. Thus, the adjustment unit can be used to adjust the position of the workpiece relative to the work table to adjust the working distance of the workpiece, thereby facilitating a user working the workpiece. When it is desired to remove the filter, endothelization of the sleeve has typically occurred but since the sleeves are a removable component part of the anchoring arms, the entire filter device can be retrieved thereby leaving the endothelized sleeves remaining in place on the interior wall of the patient’s vascular vesse.