iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad mini 3 (Cellular), released on 2018-04-24T17:06:40Z. The update package is 1.26 GB. This is a delta (partial) update that requires 10.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a9c3545c489b7d17636df9a953b42e877baea967.zip.