The Electromagnetic system features long thin strip EM labels that is suitable to be placed in books. As such it is widely used to protect libraries from theft. The unique feature of the EM strip is also that it can be reactivated after deactivation. This perfectly fits a libraries application where the book needs to be deactivated upon borrowing and reactivated upon return. The EM setback of the EM system is the close detection range of its antennas that make it not so suitable for most retail outlets.