Help? EF100-400/4.5-5.6 L II IS, USM vs USM II

[WorldFilm13]

I feel dumb but cannot tell if a lens I have is USM or USM II. I know they didn't print the "II" on the lens so how do I know?! Thanks, as I eat my humble pie.

[WorldFilm13]

Great insights! Thanks everyone. It's funny, the lens I have has a conventional zoom, but does not have the II printed on it. So... sort of walks the lines of both most recent answers. I no longer have a camera on which I can mount this either to pull metadata, but that was a great idea that didn't occur to me. It's okay, it would have helped in selling it to know, but I'm comfortable with this remaining a bit of a mystery. Mysteries make the world a bit more interesting 🙂 

Really appreciate all of you,

WorldFilm13

[shadowsports]

And still no image?  Take pictures of the lens, front, side, various angles and we'll identify it for you.  

Its only a mystery because you won't help us help you.