Prevent your personal data from being illegitimately copied without you even noticing! Always keep your credit cards, bank cards and other cards with electronic data in these RFID card protectors. This way, they are simply but effectively protected against skimming and electronic theft. - Protects credit cards, bank cards, public transport cards etc. against electronic theft. - Simple but effective: just slide your cards in these sleeves. - One sleeve contains up to 3 cards. - Small and slim to easily store them in bags, wallets and even pockets. - Aluminium alloy blocks frequencies from 10 KHz to 5.8 GHz.