The Asus ZenFone Selfie (Z00UD / ZD551KL) reached a significant milestone with its official update to Android 6.0.1 Marshmallow. While stock updates are standard, "repack" firmware versions are often preferred by the enthusiast community for their ability to streamline the installation process, especially on devices with modified recovery or root access. Core Specifications of the Marshmallow Update The official Android 6.0.1 Marshmallow update for the ZenFone Selfie (ZD551KL)

Debloating: Removal of unnecessary ASUS pre-installed software to free up RAM and storage.

Custom Recovery: Often requires or includes TWRP (Team Win Recovery Project) to facilitate the flashing of the repacked .zip file.

This is the safest method for users on standard stock software.  Download the matching firmware for your SKU (e.g., WW).

Download: Get the correct ZIP file from the Asus Official Support Page.

Firmware 60.1 repack is a re-packaged version of the original 60.1 firmware for the ASUS ZenFone Selfie (Z00UD). This firmware version brings several bug fixes, security patches, and performance improvements to the device.