iPadOS 10.3.1 (build 14E304) is an official Apple over-the-air update for the iPad Pro 12.9-inch (Cellular), released on 2017-04-03T17:00:16Z. The update package is 547.71 MB. This is a delta (partial) update that requires 10.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b42e6ef0280b114fada2a190616b1c0a86d5835f.zip.