The SignalVault provides the best RFID protection available for credit and debit cards. The SignalVault uses E-Field Technology to make your payment cards invisible to hackers trying to steal your information. One SignalVault fits in any wallet, it does not require batteries, lasts 6-9yrs and protects all cards within range of the E-Field (2 inches). Using cutting edge technology, the SignalVault approaches RFID protection from an entirely new angle. Instead of shielding your cards with a metal wallet or sleeve, the SignalVault forms an electronic field or E-Field around it whenever it detects a RFID reader. Any and all payment cards within the E-Field are made invisible & undetectable to hackers.