iPadOS 11.2.1 (build 15C153) is an official Apple over-the-air update for the iPad mini 4 (Cellular), released on 2017-12-13T18:07:50Z. The update package is 356.04 MB. This is a delta (partial) update that requires 11.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 339d80ea80a8ea9f45bc23d8d67e2d460629b262.zip.