iPadOS 9.9.11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad Pro 12.9-inch (WiFi), released on 2017-12-13T18:09:45Z. The update package is 1.37 GB. This is a delta (partial) update that requires 9.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 02cb69e55a91e9a77335378eec68e90067021ff7.zip.