Grabbed  this at the swap for a buck, Bonny or Billings?
Any clue as to it`s intended use?

If it is thin in profile, I believe it is referred to as a Thin/Slim Collet Wrench.

It's different for me.  Good to see you here.

Hey Oily, i`m still lurking about.
It`s fairly thin , i was wondering about the Jacobs reference aka Jacobs chucks?

Jabberwoki, I think you nailed it.

I believe they are not for a Regular Jacobs Chuck, but for a specialized Jacobs "Collet" Chuck. I didn't add Jacobs in my previous reply, because it was already there on the wrench