iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad Pro 12.9-inch (WiFi), released on 2016-03-31T16:54:24Z. The update package is 271.91 MB. This is a delta (partial) update that requires 9.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 185affcd8c83de0946bdb74b2a845ae98fd608ff.zip.