Slip Hook for Lifeboats

Iron slip hook, consisting of three parts: a hook with a disc in the straight end and rotating around an axis placed in the bend; a frame consisting of two metal strips, connected on one side by the axis of the hook and on the other by a disc and a harp; two round metal plates around the hook and frame, which rotate around an axis through the hook. At the eyes at the ends of the axis of the disc in the frame are two extra lines.