iPadOS 9.1 (build 13B5136) is an official Apple over-the-air update for the iPad 4 (Global), released on 2015-10-06T17:54:04Z. The update package is 1.21 GB. This is a delta (partial) update that requires null already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 49dd2fbe093903992b46bb5f7ea20b28f0f551b9.zip.