If you want to see how I went from this
before to after photo below, keep reading! :)
the decal to get rid of any air bubbles and help the actual decal stick to the paper better. It reactivates the bond making it stick better.
They range in prices so I suggest you check out their website to get a better idea and see all the options for different rooms. I believe they just peel off quite easily when you are ready to take them down, but they are not moveable in the sense where you can take it off and relocate them to a different wall. So be sure you know where you want it to go! I can update you when I move out of this apartment next year how it was to remove. :)