This Chain Gripper Plate stabilizes anchor chains and reduces stress on windlass when anchored in heavy seas. The two holes are used for a bridle application with two Bow Shackles (147212) to connect lines to port and starboard cleats for stabilization. Fits anchor chain sizes: 5/16", 3/8", 7/16", and 1/2". Constructed of corrosion resistant investment cast 316 stainless steel. Installs with two RH fasteners (not included).