I have an installed and lightly used heading sensor.
It comes with the NMEA0183 cable, but you can buy a NMEA2000 cable if you so desire.
Works perfect. This can serve many functions. It will give you radar plotting, AIS heading transmission, A super accurate compass, Read the garmin description for everything. Will also be a heading sensor for an Autopilot.
They sell for as low as $700 new, I am asking $500. Located in Florida.
PM please. I have paypal.