It has one set 12v output and the other one somehow finds its own voltage, I don't know how, but it seems to do so effectively: I've checked it with a multimeter!
For your benefit, I crawled round the back at the weekend: It's made by Hama, but I can't find it on their website.
They claim worldwide distribution, but don't seem to have anyone in the US, which cuts out a rather large chunk of the world!!