Sierra 781-579-035P Amega Series GPS Speedometer Features Dial Range 0-35 MPH Sender Code GPS Receiver Size 3 Included LCD heading display to show course over ground Use our GPS antenna sold sep or connect to an existing NMEA 0183 GPS device - connectors included Speed accuracy of -1 MPH once moving Heading accuracy of -1 degree once moving Ideal for slow speed apps like pontoon boats and for high speed performance boats w pitot tubes Black dial, red graduations, white numerals, vivid white poin