Measuring Rolling RulerFeatures: (Multi-function): Can be used as a compass, horizontal ruler, ruler, protractor, circle - template and angle template. (Practicability): Combination roller rulers, ideal for drawing vertical lines, parallel lines, graphs, charts, circles, 3D drawings, etc. (Wide Application): Great for Students, Artists and Designers (Multifunctional Parallel Ruler): Easily draw horizontal and vertical parallel lines, draw circles, curves, arcs and other geometric figures. Use the built-in protractor to measure and draw angles. (Integrated Sliding Roller): Suitable for use on drawing paper and canvas. The drawing is stable and not easy to tilt. Various formulas and conversion factors are attached to the drum for easy viewing. How to use: *Using the Protractor: Align the center of the protractor on the edge of the ruler with the top of the surveying foot, and at the same time, make the scale of the protractor coincide with the reference line, then various angles can be measured on the edge of the ruler. *Draw the arc and curve: Insert the pen into the small hole at the end of the ruler to make the center of the circle, Insert another pen into another hole and rotate the body of the ruler 360 to draw a circle. Material: Plastic Main colour: clear Measurement range: 30 / 12 inch Package includes: 1 x Parallel Multipurpose Drawing Rolling Ruler Note: The data is all manual measurement, please allow 1 - 3cm error, due to the difference of light and weather. display, there will be a certain color difference, depending on the physical object received Delivery Quantity: (according to the main image)