Tissot is a Swiss watch brand you've probably heard of. They advertise in Wired and they're not astronomically priced.
I've noticed a lot of watches have interesting, see-through backs. Tissot has quite a few. It's a shame that the only thing to really see this is a sweaty wrist. But it's probably a cool feeling for the owner to know they've got this back door they only let a few select members of their inner circle know about.