Model geometry activities for the whole class using our demonstration compass as students follow along at their desks. Draw circles 2”-32” in diameter, construct and measure angles with a built-in protractor, and measure length in metric with ruler edges. Suction cup fits securely on board for accurate measurements and construction. Translucent plastic improves accuracy by allowing you to see lines, angles and shapes as you draw them. Made of shatter-resistant SAFE-T® Plastic. Measures 19.75” x 4.25”W.