Is this really DVI?

I bought a chord at Goodwill today, what I thought was a VGA/USB-to-DVI cord. Unfortunately, when I tried to hook it in to my mini displayport-to-DVI adapter, I found the DVI end of the chord I'd bought was too big.

At the top of this picture is my adapter's DVI female end. The middle chord is the DVI end of the Goodwill chord, and beneath it all is a regular DVI male plug.
As you can see, the middle plug is much bigger than the other two and has many more pins than the others... but it's still LABELED as a DVI/USB cord. What did I buy here? (like I said, I bought this at Goodwill, all I have is the cord itself, no instructions or box)

 

Well, rats and mice.
I wonder if Goodwill has a return policy... or if I'm just $4 in the hole on this.
Thanks for the reply, though!