You can draw the graphics with a protractor, or you can draw arc curves, horizontal parallel lines, and vertical parallel lines. There is a round hole per centimeter for drawing circles and ellipses. And the scale is clear, easy to observation, not easy to skew. Whether you are an artist, student, pattern maker or , this ruler is a good helper for your work or study. It can help students develop their hands-on and to draw different . Scale color: Black Weight: 16 grams colour:Transparent Material:plastic Package Contents: 1 x Measuring ruler Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.