iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad mini 2 (WiFi), released on 2018-04-24T17:05:54Z. The update package is 583.61 MB. This is a delta (partial) update that requires 11.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 56f1bd3247b87f2138968a7eec9ba7a81bae12e6.zip.