Description Versatile Rolling RulerEasily draw horizontal and vertical parallel lines. Draw circles up to 28 cm in diameter. Draw angles with the built-in protractor. Draw curves, arcs and other geometric figures. Place your hand on the main body of the ruler, pull the edge of the ruler to a horizontal line, and then move the ruler up and down to draw a horizontal line. The horizontal line spacing is marked on the counting window. Insert the pen into the small hole on the side of the ruler, slide the ruler body up and down to draw parallel vertical lines ; the length can be indicated by the scale line in the counting window. Align the center of the protractor on one side of the ruler with the vertex of the measured angle and align the line of protractor scale with the reference line at the same time, you can measure and draw different angles on the side of the ruler. Insert a pen into the small hole at the end of the ruler to make the center of the circle, then insert another pencil and paper into the other hole, and rotate the ruler body 360 to draw a circle. Wide range of applications The wheeled drawing ruler is very suitable for students, teachers, artists, designers and architects to draw and measure various geometric figures. Material: polystyrene Color: transparent Size: 310*65*20mm Weight: 90g Lens: Used for drawing horizontal and vertical lines, circles, arcs and parallel angles. Packing list: 1 x ruler parallel roll Scope of delivery: 1 piece Product color: transparent Product size: 310*65*20mm Note: Manual measurement, please allow 1 - 3cm error