"What is this" or "did this come off my car"?

Diameter is too big. (1 13/16)
If it has steel under the rubber on the edge it's for sure a ball joint boot.
Bend it and see.

It does have steel under or embedded in the top ring- it did bend. However, I just looked at my upper control arms and the ball joints and dust boots are still on them and mostly intact except for the narrow part by the stud.

@65dartman- do you mean the column seal by the floor or is there a seal between the coupler and the white plastic bearing?

Torsion bar boots or seals don't have a lip like that do they? Now that it doesn't look like it is a ball joint cup or seal I am getting concerned.