iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad 2 (CDMA), released on 2015-10-21T17:15:48Z. The update package is 805.89 MB. This is a delta (partial) update that requires 8.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c33c29a30bfb5d7a45eb6fc11c2f07a61702e315.zip.