VLF means Really Lower Frequency and is similar technological know-how used in detectors constructed for cash, jewellery, and relics. VLF detectors broadcast at frequencies measured in kilohertz starting from 3 kHz to 70 kHz. Allow me to share five explanation why you may perhaps select a VLF above a PI http://ostrza-avalon.phorum.pl/viewtopic.php?p=404315#404315