Attaches to your plumb bob and provides you with instant rewind of your plumb bob string, up and down adjustment, and an accurate sighting target. Gammon Reel  eliminates string troubles; no knots needed for an instrument setup.
Comes equipped with 6-1/2 feet of 72-lb. test orange nylon string. (String refills available.) 
Weighs only 1-1/2 oz. Size 2" x 2".