Simrad GS25 GPS Antenna. Brand New Includes Two Year Warranty.. Product # 000-11043-001.. The Simrad GS25 GPS Antenna is a high-sensitivity GPS antenna with built-in compass that delivers faster, more accurate position-update rates for smoother chartplotting functionality. It provides best in class GPS/GLONASS positioning along with industry-leading, 10Hz GPS performance for smooth and accurate location updates. This antenna provides accurate heading for stable chart orientation in the heading up mode, improved course over ground at low speeds and radar overlay on your chart... GS25 GPS Antenna