This is a voltage knob to replace diodes on internally regulated alternators with S or Sense Pins. The peak voltage will vary on manufacturer of the alternator-you have. 
If your regulator plug does not look like the one listed in the photos chances are it will not work for your application.
This voltage control knob allows you to adjust the voltage on your GM 3 – 4 pin regulator from the set point to plus one volt.
NOT VEHICLE SPECIFIC
This is for people intending to charge higher than stock voltage, so no, this is not a plug-and-play install.
they work on up to 4 alternators of the same type.
Increase charging voltage by up to 1 volt, for example 14.8 – 15.8V.
Comes in different colors
Made for car audio
 
Each voltage control knob is meticulously built, ensuring exceptional quality and durability. The careful attention to detail and the use of the finest materials result in a product that not only looks good but also performs flawlessly. The precise engineering of these knobs allows for accurate and responsive voltage.
 
We take pride in producing these voltage control knobs locally in Holly, MI, ensuring the highest standards of quality. By manufacturing them in the USA, we can closely monitor the production process and use superior materials, resulting in a product that you can trust. 
 
Our voltage control knobs:
 
Wire into internally regulated aftermarket alternator, easy to install
Increase charging voltage by up to 1 volt, for example 14.8 – 15.8V.
Choose from a variety of colors
Made for car audio