The Mr. Pen Compass for Geometry with Pencil is made for mathematics and geometry work, helping you create perfect circles and precise arcs with steady, reliable control. Made for math & geometry: Easily create perfect circles and precise arcs Draws up to 9-inch circles: Capable of drawing circles up to 9" in diameter for a wide range of tasks Versatile for drawing & drafting: Suitable for various drafting and drawing needs Robust, sturdy build: Built with durable materials for dependable use Sturdy hinge + screw adjustment: Reliable screw adjustment helps hold the radius firmly Two-leg design for flexibility: Sharp lead on one end and a needlepoint leg on the other for use on different surfaces and materials Ergonomic handle: Comfortable for long drawing sessions while supporting steady control and accuracy