is primarily identified by build number . This update marked the final major OS transition for the device, transitioning it from Android 5.0 Lollipop to Marshmallow. Key Firmware Highlights
The specific firmware version for the ZenFone Selfie Marshmallow update is often identified as 21.40.0.1692 Automatic Update asus zenfone selfie z00ud firmware 6.0 1
: Updating your device's firmware can potentially brick your device or cause data loss. It is recommended to back up your data before attempting any firmware update. is primarily identified by build number