In the world of GSM unlocking, "extra quality" usually refers to a tool that:

It generates codes that won't "hard-lock" your phone (which happens after too many incorrect attempts).

Most ZTE devices from the SFR era are "SIM-locked." This means the phone’s firmware is programmed to recognize only SIM cards with a specific Network Identification Code (NIC). To bypass this, you need an .

While unlocking doesn't usually wipe your phone, it’s always a good habit to save your contacts and messages first. Conclusion