Firmware 5.4.2 for Asus ZenFone 4 A450CG is out now. This update allows users to disable pre-installed apps and adds some new apps like ZenCircle and Photo Collage. You can download this firmware Zip package below.
Asus Zenfone 4 A400CG has officially started receiving the Android 5.0 Lollipop update (firmware version 7.3.3) in several regions round the globe. This update is available via OTA but you can also download the official firmware package from here and flash it manually.