This pendant features a built-in 13.56MHz RFID\/NFC tag.<\/strong> It can be used as a mobile phone charm, for bus or train season tickets, or for any other system requiring a proximity card. The pendant contains a tag with a tiny RFID chip and an antenna<\/strong>. It can be powered passively by the reader\/writer simply by placing it within a distance of about one inch.<\/p>\n Almost all 13.56 MHz RFID\/NFC readers can read these RFID\/NFC tags<\/strong>; however, they must be capable of handling ISO\/IEC 14443 Type A cards. Other encoding standards (such as FeLica) are available on the market but are not compatible with this product. The RFID\/NFC tag has been tested with both the PN532 NFC\/RFID breakout board and the Adafruit NFC\/RFID shield for Arduino, and they work brilliantly.<\/p>\n RFID chips are brilliant because they can be written to and rewritten more than 100,000 times<\/strong> and have a memory that holds up to 1KB of data in writable EEPROM, divided into banks<\/strong>. They also feature a permanent 4-byte ID embedded in the chip that cannot be changed, making it easy to distinguish each tag from the others.<\/p>\n These tags use what is known as the classic NFC chipset, namely an ISO\/IEC 14443 Type A<\/strong>. Newer mobile phones and tablets no longer support this chip, following the NFC Forum\u2019s decision, made around 2014, to discontinue support for this type of chip. Obviously, this is only relevant if you intend to use this RFID tag with mobile phones or tablets.<\/p>\n You can watch the Collin\u2019s Lab video on RFID. It\u2019s very interesting!<\/p>\n