Science Purchase Large Marking Wing Divider Pencil Marking Compass Circle Maker Scriber This wing divider is ideal for measuring diameters along or accurately reproducing Arcs and circles! this divider tool features a lockable wing to easily repeat Measurements and a pencil holder for use as a compass. Get precise diameters for a Variety of projects with this handy wing divider! pencil holder for use as a compass Lockable wing for repeat Measurements marking diameter: 1/2 to 30Leg length: 12