iPadOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2018-05-29T17:14:31Z. The update package is 738.5 MB. This is a delta (partial) update that requires 11.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c3252774caaf38e360ec34af708010dda1877efe.zip.