Hmm when I test coins in the all metal mode the large two digit number in the middle is much lower then when in disc. I thought that number identifies the object but I guess not. The manual states the arc across the top identifies the object. Guess I will have to retest my coins and check that as I wasnt understanding. Ive got an area I want to detect that many yrs ago gave up some barbers and indians. Havent been back in ages. Lol.