a minimal thickness d a a decreasing width b a and ultimately a greater thickness d a lead to the desired effect of having free space in a region near the strip lens 5 for being able to arrange adjacent components so that acting bending forces can be transmitted onto the strip lens 5 without a significant resistance the spacer strip 7 has a flexural strength that is as low as possible but has a high compressive strength in particular the low flexural strength is achieved by virtue of the spacer strip 7 having a design with slits the slits 14 are distributed over nearly the whole length of the spacer strip 7 and are preferably only spaced apart with a relatively large distance where provision is made for bores 8 provided with a thread for the purpose of connection to the support strip 1 the slits 14 are open toward a longitudinal side 7 2 opposite to the longitudinal side 7 1 and extend over the whole width b a thereof the material remaining below the slits 14 referred to as slit base below has a constant residual thickness d ar which is selected to be as small as possible since the dependence of the flexural strength on the dimensions is substantially given by the thickness in the direction of an acting bending force it is not the thickness of the spacer strip d a but rather the residual thickness d ar which is decisive for the flexural strength of the spacer strip 7 the smaller the.