To be used as a ruler, meaning to draw straight lines, it is good. As a measuring tool, in no case. At 50cm it loses one and a half mm, which is an unacceptable deviation. I checked it with other rulers and measurements, as well as with the long side of an A4 glue stick which is standard 29.7 cm, and everything shows that it underestimates the measurements. German-made otherwise. Nothing is left standing. So, if it expands a little due to temperature during the summer, it will measure even more differently from others, right? Unacceptable. Avoid it.