NFC Horizon cloning

I have purchased a Horizon ring with 2 x NFC chips. My hope was to copy my work access card (4 byte Mifare classic) onto one chip and my work printer NFC credential (7 byte Mifare ultralight) onto the second chip. I have also bought an Arduino Mega 2560 (clone) and an Elechouse PN532 RFID reader.

I can read the UID details for the two credentials, but have no idea how to store the information and then write to the ring (or even whether it is possible as I understand the ring has 2 x 7 byte chips).


  1. Is it possible?
  2. Where can I get the necessary Arduino sketch?
  3. How do I use it?

Many thanks to any help provided.

With the traditional lock and key, you had a lock that only took one key…but you could make copies of that key.
With RFID access control you have a lock that you tell it what keys to take and every key is different.

The NTAG 216 is not cloneable.
The printer you would need to talk to your IT dept and enroll your tag into the system as an additional key.

The NTAG216 is not a Mifare classic chip.
You could probably clone the Mifare classic access card to an xM1+. But that’s a glass implant, not a ring.