45cm Classroom Compass Ruler for Chalk and White Board Marker. For whiteboards and blackboards. Can be adjusted. Introducing our 45cm Classroom Compass Ruler, specially designed for use with both chalk and whiteboard markers, making it ideal for both whiteboards and blackboards. This versatile tool is equipped with a compass feature that can be adjusted to create precise circles and arcs on your board surfaces. With a length of 45cm, it provides ample reach for creating large-scale diagrams, graphs, and illustrations. The adjustable design ensures flexibility and ease of use, allowing you to customise the size of your circles with precision. Whether you're teaching in the classroom, presenting in the boardroom, or illustrating ideas in a workshop, our Classroom Compass Ruler is the perfect tool for bringing your lessons and presentations to life with accuracy and clarity.