iPadOS 12.1.1 (build 16C50) is an official Apple over-the-air update for the iPad Pro 12.9-inch (WiFi), released on 2018-12-05T18:09:08Z. The update package is 420.74 MB. This is a delta (partial) update that requires 12.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 3584f2da635caca4a49e4d6baa4b375c91110732.zip.