Some of these type toilets have a tank that is mounted in the wall. Whether that is the situation with this one, I don't know. As for the flush handle or button, it's probably on the far side of this picture where you can't see it. I would think that this is a little trickier to install than a standard design toilet. And, as cool as the design is, you should check out reviews for how well this actually works. There's nothing worse than spending big bucks on a toilet that doesn't actually do the job you want it to.

You might want to talk directly with a retailer of this product to get your questions answered precisely.

Here is a link that might be useful: Duravit

It looks like that is the entire toilet. The other Duravit items which had standard water closets on them were shown with the water closets visible. So that makes me think that the image above is an image of the complete washdown toilet assembly.

I looked up washdown toilets, and found some info on another site. I've pasted the url below.

It turns out that a washdown toilet uses a different flushing mechanism than the one we're used to. It is supposed to help conserve water.

Here is a link that might be useful: what is a washdown toilet?

Oops, my bad. Turns out Kudzu's right, the water closet IS hidden behind the wall. Installation diagram from the other site is at the url below.

I guess the selling point then is the fact that it conserves water. It will be a pain to install in an existing bathroom because you would have to break into the wall that it goes into. But if your bathroom is in the process of being built (no walls yet), then go for it :)

Here is a link that might be useful: installation diagram for hidden water closet