DESIGNED FOR THE CLASSROOM -- This large magnetic protractor is perfect for demonstration on a whiteboard. It's marked up to 30cm and 10 inches. TEACH STEM -- This jumbo tool ensures easy demonstration of math, engineering and geometry concepts. Use it to teach measurements, angles and shapes. PRECISE DRAWING TOOL -- Protractors are perfect for art, which requires exact shapes. This handy, magnetic geometry tool is perfect for creative classrooms. COMPLETE YOUR GEOMETRY TOOLBOX -- Pair this protractor with other Learning Advantage Dry Erase Measurement Tools: Straight Edge (Amazon # B001UFWJIA) and Triangles (Amazon # B001UG0BOS, B001UG3ER4). BUILT TO LAST -- The protractor is made from durable plastic which allows it to handle numerous drops and years of use in the class setting. EASY TO CONTROL -- Grasp this oversized tool with ease! The included magnets ensure stability while drawing, and the ergonomic handle ensures greater control during use.