This does exactly what it is intended to do. It allows me to hang my Deco M9 Plus on the wall at the electrical outlet.
However, all that is in the box is the plastic device. There are no instructions or any kind of paperwork. The only instructions you really need is how to wind the cord inside the bottom of the plastic piece. See the 5th picture in the listing on Amazon for a picture of how it should be wound the groves on the inside.