iPadOS 11.4 (build 15F5077a) is an official Apple over-the-air update for the iPad Air 2 (WiFi), released on 2018-05-14T17:16:58Z. The update package is 247.64 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: f48a21a6af0e6848e7429230ee176297b44911be.zip.