iPadOS 9.9.11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2017-12-13T18:08:15Z. The update package is 1.52 GB. 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: 9153c63fb74912dddc06e979b1080e4776da1d9f.zip.