Auto Meter 5291 Speed Sensor for GM & Chrysler with 7/8" x 18-Thread Speedometer Cable

Required for vehicles with mechanically driven speedometers with 7/8" - 18 threads per inch speedo cable ends. The unit will determine your miles per hour while transferring information electronically to your new programmable speedometer. You will need to drive a measured mile to calibrate the Speedometer. Allows for any tire size & can be re-programmed for changes in tire sizes or gear ratios. Speedometers sold separately above. Not required if a factory electronic sender is fitted.