What is  EAS ?
Electronic Article Surveillance (EAS) is a technological method for preventing shoplifting.It 
 usually involves  three components:
1.Electronic Antenna
2.Deactivator or Detacher
3.Electronic Tag
Special tags and labels are fixed to merchandise or books. These tags or labels are removed or "deactivated" by  the clerks when the item is properly bought or checked out.Labels are deactived using a "Label Deactivator".
While ringing up purchases a cashier should pass each product label across the "Deactivation Pad".To remove a Hard  Tag a cashier uses a "Detacher" which releases the pin.After a label is deactivated or a tag is removed the  customer can then pass by the antenna without any alarm.At  the exits of the store, a detection system sounds an  alarm or otherwise alerts the staff when it senses active tags are passing by.