Sierra 781-683-080P Arctic Series Speedometer Features: Dial Range: 0-80 MPH 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 Scratch-resistant domed glass lens Enhanced illumination: through-dial and perimeter lighting for excellent readability at night U.S. and metric scales Optional add-on eyebrow or square bezels available (see Gauge Accessories for details