Hand Held Metal Detector features Fully Automatic self adjusting circuits. Inbuilt battery charger. Detects all metal objects, ferrous & nonferrous including stainless steel. Very quick & clear response to metal objects with proportional audible (buzzer) & visible (LED) indicators. Will not affect cardiac pacemaker & magnetic tapes. Fill strength does not exceed the limit set by the NILECJ-0602 standard. Buzzer sounds continuously when battery needs to be changed or recharged.