Material and visibility - Made of transparent PVC plastic, lightweight and portable. The clear surface lets you see underlying marks, so important numbers or words aren’t obscured while you draw. Function and versatility - Rolling drawing ruler (parallel ruler) for precision work. Easily draw horizontal and vertical parallel lines, as well as circles, curves, arches and other geometric figures. Applications and audience - Ideal for students, teachers, artists, designers and architects to draw and measure a range of geometric figures with clarity and accuracy. Portability and durability - Low-friction, smooth drawing experience with a clear scale for easy observation. Constructed from high-quality PVC for long service life. Use scenarios - In math class or engineering drafting: create parallel lines and precise circles or arcs for geometry problems. - In architecture or design: lay out plans, scale drawings and measured features with reliable guides. - In art and graphic design: draft clean geometric shapes and guides to enhance layouts and compositions.