iPadOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad Pro 9.7-inch (Cellular), released on 2017-12-13T18:09:28Z. The update package is 1.08 GB. This is a delta (partial) update that requires 10.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 61169c43286664537f11fb234a21f1532e350523.zip.