VLF means Incredibly Lower Frequency and is the same technology Employed in detectors constructed for coins, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz ranging from 3 kHz to 70 kHz. Here are 5 explanation why you would possibly choose a VLF over a PI Minelab’s GPX https://archives.profsurv.com/forum/Professional-Surveyor-Magazine-Discussion/Education/-151484.aspx