Speedometer Calibrator | Gas | Ford F-150 /Ranger | 2015-2020 | Rough Country | 90020Put the finishing touch on your lifted vehicle with Rough Country'sSpeedometer Calibration Device! This easy to use Speedometer Calibrator helps you quickly and easily reprogram your vehicle's speedometer to match the output of your larger tires. Your vehicles computer is designed to track the speed based on your stock tire height. When upgrading to larger tires, there will be a discrepancy between your actual speed and the readout on your