iPadOS 12.1.1 (build 16C50) is an official Apple over-the-air update for the iPad 6 (Cellular), released on 2018-12-05T18:09:39Z. The update package is 309.15 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: addff22159b7f39c0d31412794d9ca9b1a4ff8ac.zip.