Eliminates string troubles; no knots needed for an instrument setup. Attaches to plumb bob. Provides instant rewind of plumb bob string, up and down adjustment, and a target on the reel. Comes equipped with choice of 6-1/2 or 12 feet of 72-lb. test orange nylon string. String refills available. Weighs only 1-1/2 oz. Size 2″ x 2″.