iPadOS 8.4 (build 12H4086d) is an official Apple over-the-air update for the iPad Air (WiFi), released on 2015-04-27T17:47:04Z. The update package is 141.1 MB. This is a delta (partial) update that requires 8.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: cce5bbbbcdcc4692683f26cccad4298f40df1ab9.zip.