iPadOS 9.2.1 (build 13D15) is an official Apple over-the-air update for the iPad 4 (GSM), released on 2016-01-19T17:59:15Z. The update package is 965.06 MB. This is a delta (partial) update that requires 8.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 4500aac946eebc8745f5e64962f816d895d6f4c3.zip.