2PCS/lot IC Card Protection Sheath RFID Shielded Card Sleeve NFC security card prevent unauthorized scanning Color white Value of less than five US dollars can not provide tracking number, please understand. Product features RFID Security card can help users prevents strangers reading your IC banking card, ID card and transit card and RFID smart cards, the complete elimination of payment card wallet of NFC applications, such as bank cards, bus cards were fraudulent, risks such as leakage of personal information. Product description Card sets with conductor layers in the body, so when you put the card into the holding Chamber, outer conductor can isolate the bank card to make NFC devices even closer to contactless RFID cards, card in protective sleeve, you can’t get the card information, effectively guarantee the information security. Design principle RFID Security card sets is based on Farah subsection cage principle design of, NFC/RFID communications is a radio communications technology, its signal transmission using has electromagnetic make variable field, this electric magnetic field spread in meet Farah subsection cage principle of protection card sets surface will was “transparent” passed to card sets of another side, and in protection card sets of capacity reset cavity was is detection not to any make variable of electric magnetic field (because according to Farah subsection cage principle, internal everywhere potential equal, no mobile of charge), so, NFC chip within the card sets will not respond to external electromagnetic communications. NFC chip cannot be absorbed from within the security card sets NFC card reader power transmission, so there is no power to start its internal need for power the electronic structure, making even closer to NFC devices IC banking card in protective sleeve also failed to get a bank card information, effectively guarantee the security of your bank card information. Product description Color: White Size: 92 * 63 mm Tip: each card can hold one card.