crucial. Signaling devices with XENON technology, such as the models in Pfannenberg's PYRA ® series (PYRA ® X-S, PYRA ® X-M and PYRA ® X-L), as a rule cover a wider area than comparable products with different [...] a minimum light intensity of 0.4 lux/m² must be achieved under the defined measurements. Furthermore, visual signaling devices must emit white or red flashing lights at a frequency from 0.5 Hz to 2 Hz [...] sub-item 6.4.8 in VDE 0833-2 (visual signaling devices for alerting persons). The product standard also requires the devices to deliver a specific light output and light distribution. For example, it specifies