iPadOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad 5 (Cellular), released on 2017-12-13T18:08:56Z. The update package is 333.03 MB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 48b08dc4707fd9ec49aadda9fc824d685a74d384.zip.