iPadOS 8.1.3 (build 12B466) is an official Apple over-the-air update for the iPad Air 2 (WiFi), released on 2015-01-27T17:55:05Z. The update package is 567.6 MB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 640c2d098a5bdab59ec5b48928ae5b8cc8bfa327.zip.