Metal detectors work by transmitting an electromagnetic field from the search coil into the ground. Metal detector work by transmitting an electromagnetic field from the search coil into the ground. Any metal objects (targets) within the electromagnetic field will become energised and retransmit an electromagnetic field of their own. The detector’s search coil receives the retransmitted field and alerts the user by producing a target response. The detectors will beep and flash an LED light when it locates metal. It has a detecting depth of up to 6 inches deep for small coins and metal objects. A telescoping arm provides length adjustment while a padded arm strap and comfort grip make this metal detector easy to use for kids of all sizes. You also can’t beat the affordable price.