VLF means Incredibly Minimal Frequency and is the same engineering Utilized in detectors created for cash, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from 3 kHz to 70 kHz. Here are five reasons why you could possibly decide on a VLF around a PI Following http://inquisnower.phorum.pl/viewtopic.php?p=743421#743421