Upgrade your Hart Design GFK1200 (12") or GFK1800 (18") dovetail jig by replacing the original plastic hold down bar knobs or flat cam levers. Saves time, and your hands, especially when doing production runs. Set also fits the 12" Porter-Cable 4112 jig. Includes 4 each: Aluminum cam levers, 1/4-20 brass inserts, and 1/4-20 x 2-1/2" hex head bolts. Imported