Soft transparent clear plastic straight flat ruler, 30 cm/12 inch. set of 2, clear and blue, capable of drawing both straight lines and curves，made of eco-friendly clear plastic, with beveled edges, no sharp edges, will not break and splinter, can be used to measure cylinder objects as well as to measure on a flat surface, the thickness of the ruler is 3mm, it's elastic and sturdy, can be used for a long time， dual Metric and US standard scales: 30cm/12inch, centimeters are further annotated with sub-marking of millimeters, inches with sub-marking of 1/16 inch, you can position your line drawing and measurement easily and precisely，and adaptable for many uses: for mathematics, geometry, for school, home, office, for children and adults.