These tags are removed or deactivated by the clerks when the item is properly bought or checked out. At the exits of the store, a detection system sounds an alarm or otherwise alerts the staff when it senses active tags. For high-value goods that are to be manipulated by the patrons, wired alarm clips may also be used; these, being less common and technologically less mysterious, are not covered by this article.
There are several types of EAS systems. In each case, the EAS tag or label is affixed to an item. The tag is then deactivated when the item is purchased (or legally borrowed) at the checkout desk. When the item is moved through the gates (usually at a door to the premises), the gate is able to sense if the tag is active or deactivated and sound an alarm if necessary.

These tags are removed or deactivated by the clerks when the item is properly bought or checked out. At the exits of the store, a detection system sounds an alarm or otherwise alerts the staff when it senses active tags. For high-value goods that are to be manipulated by the patrons, wired alarm clips may also be used; these, being less common and technologically less mysterious, are not covered by this article.
There are several types of EAS systems. In each case, the EAS tag or label is affixed to an item. The tag is then deactivated when the item is purchased (or legally borrowed) at the checkout desk. When the item is moved through the gates (usually at a door to the premises), the gate is able to sense if the tag is active or deactivated and sound an alarm if necessary.