You argue -- correctly, I think -- that the pendant cannot possibly block the cell phone radiation. That's not what the ad, as reproduced by you, says it does, though. It says that it blocks the negative effects on your DNA, and even reverses existing damage. This implies that its effect is to heal the damage as quickly as it occurs -- or more quickly to reverse the effect.
This means, assuming that it heals the whole body and doesn't need to be applied to the point of damage, that wearing it around the neck is fine, and that there is no need to block the radiation coming from your cell phone.
This doesn't mean, though, that this is real. It seems pure, classic talisman magic to me, even though they have described a controversial (though possibly real) modern "demon" against which it is to act. Personally, I don't believe in the efficacy of talismans except as placebos, and think the probability is very high that this is a pure scam, with almost all the remaining probability on self-delusion by the purveyors.  |