like a visa card,it build-in chipset which made by more than 10kinds of ferrier absorbing materials and many rare elements can absorb electromagnetic radiation.Just ware it in front of you chest and it will protect you away from electromagnetic radiation. Suitable for: pregnant women,white-collar,old people,people who long stay in low radiation environment,banking,radio,film and television,IT, electricity,telecommunication,civil aviation,railway,medical treatment,computer training school and so on.