iPadOS 9.2.1 (build 13D15) is an official Apple over-the-air update for the iPad 4 (WiFi), released on 2016-01-19T17:59:14Z. The update package is 27.19 MB. This is a delta (partial) update that requires 9.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8538f00bd6a36ad991ac703a1b00fd89fea07273.zip.