VLF means Very Small Frequency and is the same technology used in detectors constructed for cash, jewellery, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from 3 kHz to 70 kHz. Listed here are five explanations why you may choose a VLF more than a PI Our http://nec.phorum.pl/viewtopic.php?p=763265#763265