Features:1.Foil sleeve is made of foil material , its function is to eliminate electromagnetic interference, shielding electromagnetic radiation damage to the IC card. Both airtight, every light, anti-static, anti-RF energy.2.Aluminum ferrules to avoid bank card, second-generation resident ID card, information card, social security card or other magnetic disappearance information leakage.3.Extremely lightweight and flexible; our sleeves won't add bulk or weight.4.The function is to eliminate the damage of electromagnetic radiation to the IC card. At the same time, it has the functions of air tightness, light isolation, anti static frequency.5.Extend the useful life of smart ID cards.6.Aluminum foil ferrule is made of soft electromagnetic shielding material.Scope of application:1. It is suitable for anti-electromagnetic interference of various ID cards;2. It is suitable for preventing various non-contact IC card chip circuits from being damaged, preventing information leakage and information theft on non-contact IC cards; avoiding the loss of information on IC cards.Note: This is a blank, empty space can be posted Jewelry.Specification:Materail: Aluminum foilSize: 9x6.2cm/3.54x2.44 (LxW)Color: SilverWeight: 20gPackage included:10 x RFID Holder Blocking Cases