Mercury - Next-Gen ERC Extension Harness Kit (Single) 5-Foot Extension 98-8M0173751. OverviewThis five-foot extension gives a single-engine Next-Gen ERC setup a little extra reach when the stock harness comes up short. It's handy on boats where the rigging path takes a sharp turn or the control station sits farther from the rig center than expected. Instead of forcing the wiring to stretch or bend too tight, this piece lets everything run in a calmer, cleaner line. It's a simple fix that makes t