iPadOS 9.9.13.1 (build 17A6844) is an official Apple over-the-air update for the iPad Pro 12.9-inch (Cellular), released on 2019-09-24T17:10:50Z. The update package is 2.72 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 521b5865fad2047f971a3812c65995362feb0bfd.zip.