iPadOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPad Pro 12.9-inch (Cellular), released on 2018-03-29T17:10:55Z. The update package is 585.36 MB. This is a delta (partial) update that requires 11.2.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c3495db31dcc29464506227cd889453e663b3833.zip.