iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Pro 12.9-inch (WiFi), released on 2018-04-24T17:08:44Z. The update package is 585.29 MB. This is a delta (partial) update that requires 11.2.5 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 681a0628d1bca23e887bd112281225777546588b.zip.