The advantage is simply that you can install the drill tray completely without glue, suction cups or holes. The fixings for the tray are fixed with vacuum on the wall. Effected by exposing the so-called attachment Locs on the wall, is the small pump it and so attracts 4x the air. And Zack, the holder will not budge! To remove you just have to push against the valve and lift the vacuum so again.
The installation is of course also gets own way, but I found it easier with the help of a second, because with one hand fixing in place and pulling it with one hand pump, is a bit cumbersome. Furthermore, one must also not as earlier measure and mark how far apart you have to place the mounting Locs.
But as I said, the installation also works alone.
The included manual is very short, much explanation is also not needed.
In short, the installation is very simple, the holder will not budge and creates order in the bathroom. I am completely satisfied.