Exeter RFID smartphone card wallet. Many new credit cards contain Radio Frequency Identification chips which offer convenient scanning and information sharing at the cost of security and privacy. This protector will block RFID signals and protect valuable information stored on RFID chips from unauthorised scans or unwanted readers. It allows you to hold 2 cards or IDs. The adhesive tape on the back allows you to apply the wallet on smartphones with a flat back. Aluminium foil.