The sign you're referring to is a "Length of a distance still ...m" sign. This traffic sign indicates that there is still a specified distance ahead, typically related to a specific situation, such as a speed limit zone, construction area, or a zone that requires special caution, like a pedestrian area or an animal crossing.

The number of meters (m) indicated on the sign represents how far you are from the start of the area or condition specified. For example, if the sign states "Length of a distance still 100m," it means you have 100 meters to prepare for whatever situation awaits ahead, like reducing speed or being ready to stop.

In essence, this sign is used to inform drivers of the upcoming road conditions, allowing them to adjust their driving behavior accordingly. Always pay attention to these signs, as they can indicate important changes in traffic regulations or road safety.