VLF means Very Small Frequency and is similar technologies Employed in detectors built for cash, jewellery, and relics. VLF detectors broadcast at frequencies calculated in kilohertz ranging from 3 kHz to 70 kHz. Here are five explanation why you could select a VLF above a PI The subsequent metal detectors http://ostrza-avalon.phorum.pl/viewtopic.php?p=399658#399658