The 16-digit length is part of ZTE’s security for their Snapdragon-based chipsets (often the MDM9200 series in the MF60). The algorithm used is a variant of the , which older calculators (v1 or v2) cannot crack.
Insert a non-accepted SIM card and enter the code when prompted via the WebGUI (usually at 192.168.0.1 Reliability Zte Mf60 Unlock Code Calculator 16 Digit
But for many users, the MF60 arrived with a digital shackle: the SIM Lock. And thus began the hunt for the holy grail: the The 16-digit length is part of ZTE’s security