GDI geophysical instruments established in 1996. Our products are covered by 2 year warranty. GDI manufacture a multi line of metal detectors, long range locators for gold, magnetometers, geophysical detectors for location of voids, tombs, tunnels, crypts, metal detector 3D data logger, custom made metal detector coils. Pendulum and dowsing rods. Treasure hunting, Industrial and archaeology applications. Worldwide sales network. Best prices on retail/wholesale for our products.