VLF means Really Very low Frequency and is the same technological innovation used in detectors crafted for coins, jewellery, and relics. VLF detectors broadcast at frequencies measured in kilohertz starting from 3 kHz to 70 kHz. Here are five reasons why you may perhaps choose a VLF over a PI http://classichonda.phorum.pl/viewtopic.php?p=176963#176963