VLF means Extremely Minimal Frequency and is similar know-how Employed in detectors designed for cash, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from three kHz to 70 kHz. Listed here are five explanation why you would possibly decide on a VLF more than a PI http://sarmacikrolewscy.phorum.pl/viewtopic.php?p=24911&sid=dea0ea68aacce70d12eda30cb02178c9#24911