iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Pro 12.9-inch (Cellular), released on 2018-04-24T17:08:51Z. The update package is 709.33 MB. This is a delta (partial) update that requires 11.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a2f2d59ab6bca3679202b74547fc0b5cf0a34b02.zip.