The sign you're referring to is the "Guide post warning light post," which is a type of warning sign in the German traffic system. Specifically, this sign is used to indicate that there is a guide post equipped with a warning light installed on the right side of the road.

This sign is important for drivers as it alerts them to the presence of warning lights that may be used in various situations, such as in construction zones, accident sites, or other areas where additional caution is required. The warning lights are intended to capture the attention of drivers, providing important information about potential hazards ahead.

When you see this sign, it’s crucial to remain attentive and prepared to adjust your driving behavior accordingly, as it indicates that safety measures are in place to guide you through or around a specific area. Always be cautious and adhere to any additional traffic regulations or signs that may accompany this warning.

If you have any more questions about German traffic rules, feel free to ask!