Without this magnetic attachment would have to drill and dowels. Read the instructions before installing, because there is important there, where you should not install the smoke alarm and what the self-adhesive magnetic attachment does not stick, z. B. vinyl wallpaper, polystyrene, among others. A mounting plate has 2 magnets, which is glued to the smoke detector, the other plate is in the middle of the room under the ceiling. When the plates stick again, you should not remove it, because they no longer stick it and you would have to buy a new magnetic fastening or still have to drill them. Replace smoke detector with the magnetic disk to the plate on the ceiling. To remove the smoke detector sideways push of the cover plate away until it is free. Could simply pull down may solve the ceiling tile from the ceiling. Easy and fast, I can not imagine the attachment to my hard concrete floors. That alone was worth the few bucks.
