iPadOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPad Air (WiFi), released on 2015-06-30T15:51:12Z. The update package is 364.9 MB. This is a delta (partial) update that requires 8.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d2100568dc627f627d6126711ff0c6129e0ffc27.zip.