10" 250mm Divider Caliper Wing Compass Metal Marking Circles Machinist Wood SIZE:10” 250mm Compass A drawing instrument used for drawing circles and arcs. Wing Compass A compass, often large, for scribing arcs and circles, with an arced wing that helps to steady the legs in use, and with a locking screw on the arc to hold the legs firmly in position. Divider A drawing instrument similar to a compass but with two points, Used for dividing lines and stepping off distances.