iPadOS 11.4 (build 15F5071a) is an official Apple over-the-air update for the iPad Air (China), released on 2018-05-07T17:10:54Z. The update package is 173.33 MB. This is a delta (partial) update that requires 11.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 57d2ecffdc7815193a7bceb0b14c9e61832e0a00.zip.