It's not exactly a sticker; it sticks with the contact of the plastic on the glass. If you put it on a window, it's good to remove the pins to place it on the glass and then put the pins back to hold it; this way, it will last forever. I put one on without removing them, and on the other one, I removed them because I realized it wouldn't hold. I did it myself; it's relatively easy, but you need to know how they come out