Official Firmware Asus ZenFone 3 Ultra ZU680KL Android 6.0.1 Marshmallow (Flash File). Free download Official Firmware ROM for Asus. You can use it to update the device, fixing the device facing bootloop issue or any software issue.
– Make sure that Device battery is charged more than 30%. – Extract the firmware file with the latest version of winrar or 7zip. – Always check Device model before downloading the firmware file. – Also install a latest version of USB Driver before installing firmware file.