I would like to clear metal detector sensitivity follow catalog they show test piece for model IND8035 Fe:2.0mm SUS2.5mm is test piece without product. Then test piece thst come with machine is we use only to check machine condition only. why we do like this because very time when we prepare test piece from Japan that we need to check with product that is away can't use. for this time ishida will test machine with our test piece first to make sure that after we are prepare new one to you again krab