Polk Audio NMEA 2000 Compatibility Kit [NMEA2K1]NMEA 2000 Compatibility Kit This NMEA 2000 Kit allows Polk's Ultra Marine Certified P1 and PA4A to be seamlessly added to your boat's onboard NMEA 2000 network, enabling control and two way communication from your boat's Garmin and Raymarine Chartplotter Fish Finder Multi Function Display (MFD) device. Control functions include source selection, playback functions, volume up down and more. Two way communication between the Polk P1 and PA4A and your