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 735.91 MB. This is a delta (partial) update that requires 8.4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: abfba53238e344be71aa4c67a2c383c4fe251eb6.zip.