Fratbros has nothing to do with VDI. Fisher and the new BH Pros has pulltabs in the 40s. Teks Iron comprises 40% of the 0-99 scale where Fisher and BH only 20%. Having a large iron scale is good for relic hunters to fine tune iron signals. Non ferrous metals are given to the 60% left on Teks or the 80% left on Fisher/BH. All Fratbro FTP in house processing.