Six mutual over-lapping detecting zones, Simultaneous alarm from multi- zones. Sensitivity adjustable: Each zone has 100 sensitivity level. Sound & LED alarm: Both Side LED indicator ,easily show where the metal is. Automatically count passengers and alarm times. Alarm strength indicator on control panel. Password protection, only the authorized person can operate. Easy assembly: designed with only 2 pieces cables and 8 screws, simply-to-follow instruction. Harmless to human body: is harmless with heart pacemaker, pregnant women, magnetic floppy, recording tapes, etc.