Whats Missing Here?

[Sponge60]

This is the driver's side mirror on my 21 3500 Laramie. I swear I don't remember seeing this before. Is something missing? A cap or cover?

 

[superjoe83]

That's how it's supposed to be, it's the ambient temp sensor

 

[Darkside]

There’s no cover on that, the sensor is black when it’s new, but becomes more noticeable within a couple weeks when it rusts….

 

[Crusty old shellback]

Just looked at mine. Never noticed it before. But after 1 1/2 years, its still black. And it gets washed almost every week.