The Latest In Technology And The Easiest Possible Way To Add A Highly Accurate Speedometer To Your Vehicle. Autometers Advanced Gps Speedometers Require No Interface With Your Vehicle Aside From Power And Ground. Their Ultra Fast, Omnidirectional Micro Antenna Is Included For True Plug And Play Functionality And Never Requires Calibration. Configurable Rally Nav Display Shows Odometer, Trip Odometer, TimeDate, Gps Coordinates, Heading Info, Compass, And Peak Speed Recall. Quite Simply, The Easiest, Most Accurate Speedometer Available.