Mercury - Next-Gen ERC Extension Harness Kit (Triple) 10-Foot Extension 98-8M0173880. OverviewThis ten-foot extension gives a triple-engine Next-Gen ERC setup the extra reach it often needs when the stock harness won't quite make the run. Triple-engine rigs usually have longer or more complicated routing paths, and this extension keeps you from forcing the wiring into tight corners. It lets the harness follow a smoother, more natural path so the controls feel steady and predictable. It's a simpl