VLF stands for Quite Minimal Frequency and is identical technological know-how used in detectors developed for cash, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz ranging from three kHz to 70 kHz. Here i will discuss 5 explanations why you may pick a VLF over a PI http://leydis16.phorum.pl/viewtopic.php?p=1026025#1026025