Features: High accuracy of compass drawing, fine adjustment of screws, maximum opening of 45mm. With spring-loaded adjustment knob to prevent accidental leg movement. Professional Tools: Thanks to the center drive wheel for fine adjustment, you can quickly adjust the compass feet and adjust the diameter of the circle. It is firm, non-slip and has a good grip. The professional design makes drawing simple and interesting. Precision Tool: This compass can accurately draw circles in mathematics, geometry, art, and drawing. The distance range is 1 to 40 mm. You can use it for stable circular drawing jobs. High-Quality Material: It is made of solid metal with a stable and strong center drive shaft. The solid metal structure makes the drawing more accurate. It can be used for a long time. Wide Utilati...