iPadOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad mini 4 (WiFi), released on 2017-12-13T18:07:20Z. The update package is 1.1 GB. This is a delta (partial) update that requires 10.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8bcc10117faeb986aa5e05996c6064e7f2fe4def.zip.