iPadOS 12.1 (build 16B92) is an official Apple over-the-air update for the iPad Air 2 (Cellular), released on 2018-10-30T17:06:01Z. The update package is 1.25 GB. This is a delta (partial) update that requires 11.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5f6a0134b69b99377b1e7e0e5bfcd9aebc06299b.zip.