iPadOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPad Air 2 (WiFi), released on 2015-06-30T15:51:16Z. The update package is 187.84 MB. This is a delta (partial) update that requires 8.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b58196d612052355c3c54aff5e56654bceacbbe6.zip.