iPadOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad Pro (10.5-inch, WiFi), released on 2017-12-13T18:10:29Z. The update package is 345.51 MB. This is a delta (partial) update that requires 11.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 474b1d4cea98f619639089de15fdaaa2aca64213.zip.