iPadOS 9.2.1 (build 13D15) is an official Apple over-the-air update for the iPad mini 4 (WiFi), released on 2016-01-19T17:59:36Z. The update package is 237.58 MB. This is a delta (partial) update that requires 9.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7f12df8fb31e16064321a17a39bf2d38d75e2226.zip.