The Simrad GS25 GPS antenna is the ideal GPS for any navigator that requires extremely accurate and rapid vessel position and speed updates. Unlike other position-only antennas, the GS25 provides magnetic heading for accurate boat direction at any speed and for radar/chart overlay. The GS25 easily connects to any Simrad NS Series multifunction display or any NMEA 2000® network. It is fully waterproof and can be pole or surface mounted on any vessel. *Please note this product is not suitable for use with MARPA or autopilot systems which requires a rate compass such as the RC42.