Beakers glass- 100ml, 250ml & 500ml

Beakers are often graduated, that is, marked on the side with lines indicating the volume contained.

For instance, a 250 ml beaker might be marked with lines to indicate 50, 100, 150, 200, and 250 ml of volume. These marks are not intended for obtaining a precise measurement of volume (a graduated cylinder or a volumetric flask would be a more appropriate instrument for such a task), but rather an estimation. Most beakers are accurate to within ~10%.