VLF stands for Quite Minimal Frequency and is the same technological innovation used in detectors built for cash, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from 3 kHz to 70 kHz. Here's 5 explanations why you could choose a VLF in excess of a PI https://www.sociomix.com/c/ugc/best-practices-when-using-a-metal-detector/971791767879203