Mercury - 5-Pin NMEA 2000 / CAN H Extension Harness 4 m 84-879171T05. OverviewRigging doesn't always line up the way you expect, and sometimes a sensor ends up just a little farther from the backbone than planned. The Mercury 84-879171T05 Extension Harness adds four meters of breathing room, giving you enough length to route a GPS or IMU cable cleanly through the dash or along a side panel without forcing a tight bend. It's an easy way to tidy up the install and place your sensor where it actual