The Bullseye Demonstration Compass lets you model drawing activities for the whole class. The direct-view pivot point and quick-set radius indicator allow easy drawing of circles 2 in to 32 in in diameter. The compass also has a built-in protractor and dual-scale ruler. Use with chalk or a dry-erase marker. The suction cup fits securely on a board. Transparent, shatter-resistant plastic; large size (19.75 in x 4.25 in). Size: 63 x 15.2 x 0.8 cm.