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 1.2 GB. This is a delta (partial) update that requires 7.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d128fecefca46c4db9a18152e4e5c1f959f65f50.zip.