This is the UID changeable Mifare Classic 4K size magic card.
The UID can be modified ONLY with an external device (PN532, PCR532, ACR122U, Proxmark3 X, and iCopy-XS).
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.
MTools Lite App can be downloaded from Play Store and App Store.
You can also DIY the custom PN532 Reader with BLE module. See the tutorial below to know how to make PN532 work with Bluetooth.

By Proxmark3 X or iCopy-XS
hf mf gen3uid --uid 11223344556677

By ACR122U
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.

Great product! The 4k size allows me to store all of my information and the UID change feature is very easy to use.
I was skeptical at first, but this card really does work as advertised. The 4k size is great and the UID change feature is easy to use.
The 4k size is perfect for holding all of my information. Being able to change the UID is a nice bonus. Overall, a great product.
This 7 Byte UID S70 card works well with iCopy-X reader.