Material - The ruler is made of aluminum alloy material, the compass is made of iron, it will not be deformed by external force, nor will it be broken by falling, durable and easy carry, not easy to wear and break Precise Measurement and Clear Scale - Giving you accurate readings when measuring objects and drawing drawings, improving readability and clarity, clear color makes you measure easier Compass Easy To Draw Circles - By turning the center wheel, you can adjust the diameter of the circle, making it easy and fun to draw circles, the grooved compass head ensures a firm, non-slip grip that is not easy to slip off Easy to Use - You can make fine adjustments using the central drive wheel, or you can hold the compass and click the adjustable wheel to set the circle diameter quickly and accurately, which makes drawing easy and interesting Wide Application - Math geometry tool set are useful tools for architects, engineers, woodworkers and carpenters, artists, designers, students, teacher and so on, for teachers and students at any level