The EM4000 series high security electromagnet are designed for high security applications, each encoded armature plate is individually registered to only match its own electromagnetic lock, it recognizes it's own armature plate, preventing anyone from "tricking" the magnet with a separate plate. Lock status and alarm status for local and/or remote indication are on two independent relay outputs. EM4000 series are all high quality plated and performed to over a million operation that release to unlock instantly when power OFF without any residual magnetism.