This is the 4 Byte UID changeable Mifare Classic 4k size key fob.
The UID cannot be changed with NFC on Android or iOS devices.
Command to Change UID
By All-in-one PN532 or PCR532
The latest features of the MTools Lite app support modifying the UID of the Gen3 7 Byte S70 4K card via Bluetooth PN532 Reader.
The PN532 Reader can be customized with the Bluetooth module. See the tutorial below to know how to make PN532 work with Bluetooth.
Windows Program Download Link: PCSC_Mifare_Secure.
Notice: Google Drive may recognize the PCSC Mifare Secure program as a virus cause it can detect the USB devices which it’s necessary to connect the reader. Absolutely it’s a clean and powerful program. Download the zip file with the browser on PC.