 Unlike the passport book, the RFID chip in the passport card is designed to be readable at a greater distance, allowing border agents to access traveler information before they pull up to the inspection station.While a biometric passport contains a chip containing all of the traveler's information in electronic format, the RFID chip in a passport card does not contain any personal information beyond the identifying number, which is used to locate records in secure government databases.To prevent the RFID chip from being read when the card is not being used, the passport card comes with a sleeve designed to block RFID while inside.