Faraday pouch and circuitry, montage image. The Faraday pouch contains within the fabric a lining of woven stainless steel to produce what is also known as an RFID-protected (radio-frequency identification) wallet. The material doesn't stretch, rip or stain which means that it is virtually indestructible. When used in a wallet, the steel creates a Faraday cage, a shield that blocks out external electrical fields, which means no access for anyone trying to steal personal data, as well as blocking mobile phone signals.