Hi +31651328524 Thank you for your asking. The last WW firmware version of ZU680KL is Android 7 WW14.1010.1804.75. For more firmware related information, please refer to the link below Zenfone3 Ultra(ZU680KL) - SupportYou may check the current firmware version by: Settings>System>About Phone>Software information
To update the system, you may try Auto Update or Manual Update. 1. Auto Update (Easier Way) Settings>System>System update *Tap the 3 dots on the top row of "System update">Auto-update settings, for related settings 2. Manual Update (Normally be used in cross-Android firmware update or rooted/unlocked device) Download the firmware file into the root directory, aka the outermost place, of the internal storage>Reboot>Tap the "system update" notification *To perform cross-Android firmware update, please backup the device data first.
