VLF means Quite Low Frequency and is similar technologies used in detectors developed for coins, jewellery, and relics. VLF detectors broadcast at frequencies calculated in kilohertz ranging from 3 kHz to 70 kHz. Listed here are 5 explanations why you may go with a VLF above a PI What absolutely http://nec.phorum.pl/viewtopic.php?p=753869#753869