High quality metal body with durability and impact resistance. Ergonomic design for comfortable, easy use. Professional compass set with a rotary switch that controls the length of the pen handle. The two compass legs extend up to 180 degrees to form a straight line, allowing you to draw circles with different diameters. Two pieces are included for protection and organization, enclosed in a clear box for easy carry and storage. Wide application for school, woodworking, workshop or home. Suitable for students, artists, mathematicians and carpenters for woodworking, carpentry, metalworking, and related tasks. Use scenarios - In geometry class or math homework, draw precise circles and arcs with adjustable radius. - On woodworking or carpentry projects, lay out circular patterns or mark holes with accurate spacing. - In metalworking or workshop tasks, transfer measurements and mark circular features on metal stock.