I uses an Ethernet cable to directly connect two Helix 9 G3N units without having to purchase an Ethernet box. They were easy to sync and now I see the same readings in front of my boat as on the console. I also have a Humminbird 360 Imagining and see it on both devices. So this Ethernet cable gave me more options at a fraction of the cost of setting up an Ethernet network. Great product, great performance.