Recalibrate your Ford F150 or Ranger speedometer instantly and easily with the Rough Country Speedometer Calibrator. This amazing device takes all the guesswork out of setting your speedometer to give an accurate read-out after installing larger tires. In just a couple of minutes you are set and the process can be reversed if needed. The computer in your vehicle is designed to calibrate speed based on stock tire height. Larger tires cause a discrepancy resulting in the speedometer readout being incorrect. This device connects directly to the Diagnostic Link Connector Port and begins working in just a few minutes for an accurate readout. This device also updates your vehicle’s ECM to ensure accurate shift points and proper electronic stability control. The USB update cable is included. In addition, this device can also check all diagnostic codes for “check engine light” and “service needed” messages. There’s also a function to reset the speedometer back to stock prior to servicing. This affordable and accurate speedometer recalibrator makes this chore a snap. Included is a 1 Year Warranty. Download the latest software update here View installation instructions</strong