iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad Pro 9.7-inch (WiFi), released on 2018-04-24T17:08:16Z. The update package is 1.24 GB. This is a delta (partial) update that requires 10.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f2ee19759682185de4e583aef75014640533863f.zip.