iPadOS 11.4 (build 15F5079a) is an official Apple over-the-air update for the iPad Air (Cellular), released on 2018-05-17T17:01:51Z. The update package is 38.89 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: 60c7210fdd3940a7e294069e54ec90807a136542.zip.