- Metal movable joints provide wear-resistant durability for long-term use. Capable of drawing a circle with a maximum diameter of 120 cm. - Beech multi-purpose compasses can be used with whiteboard markers or chalk, offering flexible marking on different surfaces. - The plastic vacuum attachment offers strong board adhesion, is easy to use, and provides non-slip stability. It minimizes movement and reduces the risk of damaging the board during use. - The teaching instrument includes a rule set with a 45-degree triangle, a 60-degree triangle, a protractor, and a multi-purpose teaching compass for comprehensive geometry work. Use scenarios: - In classroom geometry, draw large circles on whiteboards or chalkboards up to 120 cm in diameter for demonstrations and problem solving. - Teach angle construction and measurement by using the 45-degree and 60-degree triangles along with the protractor. - Conduct stable, hands-free demonstrations on the board with the vacuum attachment to prevent slips and protect the surface.