iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Pro 2 (12.9-inch, Cellular), released on 2018-04-24T17:09:00Z. The update package is 1.38 GB. This is a delta (partial) update that requires 10.3.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 64598c9c55169d945176773d33f043764e94f03c.zip.