iPadOS 11.4 (build 15F5071a) is an official Apple over-the-air update for the iPad mini 3 (WiFi), released on 2018-05-07T17:11:00Z. The update package is 197.96 MB. This is a delta (partial) update that requires 11.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e0530a9e8400e939650c48ba6d4580d47ab5286d.zip.