According to ZTV-SA 97, Picture 2, Section D

VARIO-GUARD® is the perfect protection for dangerous traffic sections. Due to its flexibility VARIO-GUARD® can be installed in any traffic situation. Since the lower part of the VARIO-GUARD® is can be driven upon, the road marking can be applied directly on the foot section.
So - in case of narrow work zones - no extra space for road marking is required. If needed the system can be additionally supplied with plug-on bollards or reflector elements. These high quality reflector elements, which are installed on the upper part of the VARIO-GUARD®, guarantee best routing at night and in rainy or foggy weather.