The DGPS-212W improves accuracy by adding digital differential corrections. Accuracy as low as 2m can now be achieved. If the differential correction signal is not available, the WAAS correction signal will take over, giving you accuracy down to 3m. The differential signal is automatically located depending on your location. The 212W plugs directly into JRC radars and chart plotters making installation extremely simple. You can also wire the 212W into your existing equipment via a NMEA connection.