For over a decade I've ask for one small feature to a good detector. Say for instance on the Fisher F75 detector or another machine of comparable abilities. Add a two tone function in the motion all metal mode. Nothing fancy, just one tone for ferrous and another for non-ferrous. Being a computer programmer for several years I can't imagine this would be very difficult. Now on the F75, while in motion all metal mode the machine gives better depth and also gives an ID for detected meta