Typically, most VLF detectors, made today operate in the 5 to 15kHz range, while gold detectors typically operate at about 20 kHz. The increase in frequency gives a minutely greater response to tiny bits of gold, but the increased response to small targets results from them having about ten times as much gain as general purpose detectors. Increasing the frequency much above 20kHz gives a tiny bit more response in air tests, but the increase is lost as soon as the target is laid on the ground.