Versatile Rolling Ruler Easily 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. Drawing roller ruler Built-in roller, smooth sliding, stable drawing and not easy to tilt. There are parallel scales, various formulas and conversion factors on the drum for easy viewing at any time. Transparent scale ruler black printed scale of the ruler is clear and easy to observe. Marked in metric and inch. The transparent ruler allows you to draw without skipping some important graphics or texts. Material and precautions Made of impact-resistant plastic, lightweight, easy to carry, practical and durable. Note: This roller ruler is only suitable for use on relatively high friction surfaces such as drawing paper and canvas, and not suitable for use on too smooth surfaces. Widely Whether you are an artist, student, designer or architect, this drawing parallel ruler is a good helper for your work or study. It can help students develop their surveying and mapping skills and spatial imagination to meet different needs. Put your hand on the main body of the ruler, pull the edge of the ruler over a horizontal line, then move the ruler up and down to draw a horizontal line. 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 one side of the ruler with the vertex of the measured angle and align the scale line of the protractor 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 in another 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 Purpose: used for drawing horizontal and vertical lines, circles, arcs and parallel angles. Packing List: 1 x Rolling Parallel Ruler