Correct the speedometer on your modified 1994-1998 Mustang with this Abbott electronic speedometer calibrator! Also, known as an ERA for electronic ratio adapter is designed to easily allow you to recalibrate your speedometer after installing a different tire size or rear axle ratio. The Abbott ERA receives your current speedometer signal from your SN95 speed sensor (VSS) and allows you to correct the speed signal sent to the dash. Installation is simple with only four wires to hook up, a power, ground, and tapping into speed sensor signal wire and mount the box in the interior compartment. Adjustments are made easy by setting the dip switches according to the calibration chart Abbott ERA Calculator and you're ready to go. Quickly and easily adjust the speedometer on your 1994-1998 Mustang without having to reflash your ECU with this Abbott electronic speedometer recalibrator.