Asus appears to be working on bringing Android 6.0 Marshmallow update to its eligible devices, as it has started seeding the firmware to a few phones. Now, the latest handsets to receive the operating system are the Asus Zenfone 2 ZE551ML and Asus Zenfone 2 ZE550ML.

According to STechGuide (via GSMArena), the Asus Zenfone 2 ZE551ML and Asus Zenfone 2 ZE550ML have received Android 6.0 Marshmallow update via OTA (over-the-air), and the firmware file weighs 1.1GB. The update fixes bugs besides bringing features like Doze, Now on Tap, Runtime Permissions and Google Now on Tap.

The Asus Zenfone 2 ZE551ML and Asus Zenfone 2 ZE550ML came with Android 5.0 Lollipop based Asus ZenUI when they were released last year.

How to install Android 6.0 Marshmallow to your device:

- Android 6.0 Marshmallow download notification will appear on your phone screen

- Press "Download" button

- Press "Restart & Install" button

- Rebooting will begin automatically

- You will see "Installing System Update" notice when installation starts

- Upgrading begins automatically

- Android 6.0 Marshmallow will run on your device after upgrading is done

You can also manually check availability of the new software by going to – 'Settings' >> 'About phone' >> 'System updates' >> 'Check For Update'.