iPadOS 8.4 (build 12H4086d) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2015-04-27T17:47:05Z. The update package is 167.59 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: 5885d2188c84d658f26986e8405d1e91c6c436ad.zip.