Sea-Dog Stainless Steel Chain Gripper Plates. 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). Package Contents: Sea-Dog Stainless Steel Chain Gripper Plate Sea-Dog 321850-1: Stainless Steel Chain Gripper Plates