iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad mini 2 (WiFi), released on 2018-04-24T17:05:55Z. The update package is 577.86 MB. This is a delta (partial) update that requires 11.2.5 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e474b8882bc2386876dc9a13951f82e1882955d2.zip.