VLF stands for Very Minimal Frequency and is identical technologies Employed in detectors constructed for cash, jewellery, and relics. VLF detectors broadcast at frequencies measured in kilohertz starting from 3 kHz to 70 kHz. Here are 5 explanation why you may opt for a VLF in excess of a PI http://taniecirlandzki.phorum.pl/viewtopic.php?p=117860#117860