it was used as a backup helm control for my autopilot. I use Echomap to control autopilot.
owned for 2 yrs.
the back shell was damaged(as a small hole), I used a hard plastic to cover it, check the photo. but it does not affect its function on my NMEA 2000 connection. When I am not using Echomap, this GHC 20 is controlling the autopilot.

Control unit only, no cable, no NMEA connector.