Mercury - Next-Gen ERC Extension Harness Kit (Quad) 10-Foot Extension 98-8M0173881. OverviewThis ten-foot extension gives a quad-engine Next-Gen ERC setup the extra reach it often needs on bigger boats. Long rigging runs and tight corners can make the stock harness feel stretched, and this piece helps you avoid that. It lets the wiring fall into a smoother, more natural path so the controls feel steady instead of strained. It's a simple add-on that makes a crowded quad-engine layout easier to de