VLF stands for Quite Low Frequency and is identical technological innovation Employed in detectors developed for cash, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from 3 kHz to 70 kHz. Here are 5 main reasons why you might choose a VLF around a PI Next, http://opensource.platon.sk/forum/projects/viewtopic.php?p=12844765#12844765