This is a blank 13.56MHz RFID/NFC laundry tag - often used for laundry but also general tagging. The tag contains a small RFID chip and an antenna, and is passively powered by the reader/writer when placed a couple inches away.
These can be read by almost any 13.56MHz RFID/NFC reader but make sure it can handle ISO/IEC 14443 Type A cards as there are a few other encoding standards (like FeLica) They are tested and work great with both the PN532 NFC/RFID breakout board and Adafruit NFC/RFID Shield for Arduino!
These chips can be written to & store up to 1 KB of data in writable EEPROM divided into banks, and can handle over 100,000 re-writes. You can use the PN532 NFC/RFID breakout board or Adafruit NFC/RFID Shield for Arduino to read and write data to the EEPROM inside the tag. There is also a permanent 4-byte ID burned into the chip that you can use to identify one tag from another - the ID number cannot be changed.
These use a ISO/IEC 14443 Type A chipset, which used to be the 'classic' NFC chipset. In ~2014, the NFC forum decided not to support this chipset anymore, so newer phones do not support it. This only matters if you're trying to use this tag with a phone/tablet.
RFID chip specification:
- 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
- 25.4mm diameter x 1mm / 1" diameter x 0.03"
- 0.9 grams / 0.03 oz
- Works about 2" away from reader