iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad 2 (WiFi), released on 2015-10-21T17:15:47Z. The update package is 808.9 MB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 2cd4dfd598592905017ec4a1f8fd535b278cb6b9.zip.