The one on my panel was almost 20 years old and worked fine. They are made for that application. I don't know if the new ones are the same but the one on my panel had a light inside the knob that got dimmer as the speed went down.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.