Exactly one week ago a Lenovo Group VP made a promise regarding the update to Android 7.0 Nougat for the ZUK Z2 Pro - namely, that it would be rolling out at some point this week. And it turns out that prediction was accurate after all. Starting today, ZUK Z2 Pro units are receiving the update which brings with it the latest version of the Lenovo sub-brand's own skin on top of Android too, which is ZUI 2.5.335. This is built on Android 7.0 Nougat, so owners of the Z2 Pro can now taste this iteration of Google's mobile OS for the first time, as you can see from the screenshots...
Source: http://www.gsmarena.com/zuk_z2_pro_is_being_updated_to_android_70_nougat-news-22829.php