Classic Instruments once again leads the instrumentation market with the creation of the all new SN74. With only two touches, you can now easily and accurately calibrate your speedometer.

Push the button, drive a measured mile, push the button again and you're done!

The SN74 features in-line installation between the transmission pulse signal or ECM speed output and your electronic speedometer.

• Converts all known pulse signals to 16,000 ppm or 8,000 ppm signals and includes an additional 8,000 ppm output signal for cruise control.
• Real-time calibration
• Filtered power source eliminates interference
• Will work with most aftermarket electronic speedometers
• Small enough to be mounted anywhere inside your vehicle

Product Reviews for CISN74 - CLASSIC