iPadOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2017-12-13T18:08:35Z. The update package is 526.99 MB. This is a delta (partial) update that requires 11.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 31ebd508c202ea676dd0b1054c9338607ce7447b.zip.