Which one of the following is not part of DFMD ?

A Door Frame Metal Detector (DFMD), also known as a walk-through metal detector, operates on the principle of electromagnetic induction to detect metallic objects. Its core components typically include side panels (containing induction coils), a cross piece (the top horizontal beam connecting the panels), and an electronic unit that houses the circuitry, power supply, and alarm system. Many modern DFMDs also include a remote control unit for wireless calibration and sensitivity adjustment.

A lead curtain is not a part of a DFMD. Instead, it is a critical safety component of an X-ray Baggage Inspection System (XBIS). Lead curtains are used at the entry and exit of the X-ray tunnel to shield operators and the public from scattered X-ray radiation. Since DFMDs do not use ionizing radiation, they have no requirement for lead shielding.