Handheld Metal Detector in Delhi Super Scanner HHMD in Delhi Portable Metal Detector Convenient to take It can be recharged, It needs 4-6 Hours for charging. The alarm terms is sound and light alarm simultaneously or vibration and light alarm simultaneously you can choose the operate terms optionally. When the low sensitivity on-off is pressed the metal detector will only alarm when it finds big metal object. A. Pin: 30-60 mm B. 64-Pistol: 180-195 mm C. 6 Inch Knife: 160-180 mm D. Steel Ball with 20 mm diameter :120 mm E. Any Coin : 75-100 mm