iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad 2 (Mid 2012), released on 2015-10-21T17:15:49Z. The update package is 111.43 MB. This is a delta (partial) update that requires 9.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: fb7717f205bb13d600a8a230a50c9694959fbea6.zip.