A detacher is used to remove re-usable hard tags. The type of detacher used will depend on the type of tag. There are a variety of detachers available, with the majority using powerful magnets. Any store that uses an anti-shoplifting system and has a detacher should take care to keep it secured such that it cannot be removed. Some detachers actually have security tags inside them, to alert store personnel of them being removed from (or being brought into) the store. With increasing prevalence, stores have metal detectors at the entrance that can warn against the presence of booster bags or detachers.