The military grade engineering fabric used in the VB Card shield is specifically developed to block the frequency used in RFID style credit, debit and many ID cards, namely 13.56Mhz. A full research and development document is available on request. VB HAS NEVER USED ALLUMINUM FOILS AS MOST MANUFACTURERS DO! Unlike tin / baking foil VB's fabric doesn't suffer from degradation, uses specific reflective and conductive properties to dissipate and reflect the energy used to wake the RFID card, it does not use digital jamming, nor any other digital blocking technology, it is therefore free from corruption or interception of a digitally transmitted signal.

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