Mercury - 5-Pin NMEA 2000 / CAN H Extension Harness 8 m 84-879171T09. OverviewWith some boats, the ideal spot for a GPS or IMU sensor isn't anywhere near the backbone connection. The Mercury 84-879171T09 Extension Harness gives you eight meters of reach, which is often just what you need on a center console or any hull with long rigging runs. It lets you place the sensor where it actually performs best-without stretching the cable or forcing it through tight corners.. Key Features. 8-Meter Cable