Back in February, Asus ZenFone 3 Zoom arrived with Android 6.0.1 Marshmallow on board, but now the Android Nougat update is finally rolling out. This premium handset comes with a massive 5,000 mAh battery and a dual camera setup that offers 2.3X optical zoom and 4-axis image stabilization.
According to the official post on the ZenTalk forum about the new firmware, the model targeted is ZenFone 3 Zoom ZE553KL and the new software version, after completing the upgrade, would be 20.31.49.2. The release notes mention the following three highlights: Android Nougat upgrade, support for Portrait mode, as well as performance improvements and bug fixes, next to "improved picture taking experience." The new firmware is based on Android 7.1.1 and it also brings Google Assistant and Google Now to ZenUI.
The same source points out that this OTA update needs about one week to reach all compatible devices, but those who did receive the notification yet can check manually via Settings>About>System Update.