When mounting a Hide-a-Hose system, you have two options: internal or external. When mounting internally, you run the piping behind the drywall, and you'll have a panel that you flush mount to the wall.

But when mounting externally, you need a box to attach the flush mount panel to. All you do is screw it to the wall and hook up your pipes, and flush mount the panel. It is 3D printed, but don't freak out. It's Carbon fiber reinforced super nice printing, so it's on par with an injected modeled part. It just has a few lines in it.