Addicore RFID AddiKit with RC522 MIFARE Module, RFID Cards, and RFID Fobs (Arduino Compatible) Includes 1 RC522 MIFARE RFID modules, 3 key ring FOBs, 5 RFID cards and 1 tag with link to Getting Started Guide and code Ideal for use in such things as credit cards, key fobs, and pet collars, because there is no need for battery power Can read at distances of 5cm (1.97in) for cards, 3cm (1.2in) for fobs Operating Frequency: 13.56MHz Each card has a unique ID number to prevent counterfeit and each transmission passes through 3 sets of 28-bit encryption, alleviating possibility of interception