The Humminbird Advanced Accessory System Interlink Module shares GPS, waypoint, and route information between two network capable plotter or combination units. The units may be daisy-chained to allow for systems with more than two plotters. The Interlink Module does not pass fishfinder data between units. Compatible with the following units: 718, 728, 768, 778c, 778c HD, 788c, 788ci, 788ci HD, 788ci HD DI, 798c SI, 798ci SI, 798ci SI HD, 858c, 898c SI, 917c, 957c, 958c, 997c SI, 998c SI, 1157c, 1158c, 1197c SI, 1198c SI.