Mercury - Remote Display Extension Harness Rigging Accessory 84-8M0215698. OverviewThis extension harness gives you the extra slack you need to place the remote engine display where it actually fits on your helm. It's great for boats where the standard cable just won't reach or the wiring has to snake around tight corners. It plugs straight into the existing display connection, so you're not cutting or splicing anything-just a clean, simple length boost to make the install easier.. Key Features