The Android 8.0 Oreo update was pushed by Asus on March 12, 2018, and it’s tagged as version V15.0410.1802.34. It won’t be available for all Zenfone 4 Pro (ZS551KL) users at the same time, so you’ll need to keep checking for updates under Setting – About – System Update until you see the Android Oreo update. Besides being based on Google’s Android 8.0 Oreo mobile OS, the new software update for Zenfone 4 Pro (ZS551KL) smartphones comes with power consumption improvements, a new “Long screenshot” function, as well as the PlayTo function, which replaces the Cast function used in previous versions.