Constant Voltage Regulator for 1967-1968 Mustangs.
This new constant voltage regulator features solid state technology for smooth gauge performance with no adjustment needed. Original units use mechanical contacts that open and close causing gauges to fluctuate needing to be adjusted manually with a screw driver.
When this part goes bad, it may cause one or more of the dash gauges to stop working properly. So when you are installing new dash gauges, you may want to replace that old regulator to prevent this from happening to you.