This is a MiFare Classic keychain fob - often used for electronic locks or customer identification. The tag contains a NXP S50 chip and an antenna, and is passively powered by the reader/writer when placed a couple inches away. Can be used with NFC Shield.
- 1 KiloByte (8 KiloBit) non-volatile EEPROM storage
- Built in encryption engine with 48-bit key
- 4 Byte unique identifier burned into the chip
- 13.56 MHz frequency