Wide applications: versatile measuring ruler with a protractor to draw the desired figure can also draw arc curve horizontal parallel line vertical parallel line enough size for drawing in a length of 12 inches/ 30 cm More details: each centimeter has a circle hole for drawing circles and ellipses; This drawing ruler is built in roller clear scale easy sliding stable drawing not easy to skew clear scale easy to observe; There are various formulas on the roller which can be calculated quickly in use Multiple uses: whether you are an artist student pattern maker or designer this measuring rolling ruler is a good helper for your work or study; It can help students develop their own manual skills as well as their imagination to draw different design pictures Quality material: our measuring ruler tool is made of transparent plastic; It is light-weighted easy to carry; Transparent material allows you to draw without ignoring some important figures or words Package includes: 2 pieces measuring rolling ruler 2 rulers can let you keep one in school or office and another ruler at home in case you need it