iPadOS 11.4 (build 15F5061d) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2018-05-01T17:05:46Z. The update package is 212.64 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0ef46fe96e864ecfb6fb473cbe1d8db2b7b4f0cc.zip.