iPadOS 8.4.1 (build 12H321) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2015-08-13T18:05:12Z. The update package is 433.9 MB. This is a delta (partial) update that requires 8.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c027278556d3859dc996d277b5eb4673b28911a8.zip.