iPadOS 12.4 (build 16G5077a) is an official Apple over-the-air update for the iPad Air 3 (WiFi), released on 2019-07-16T17:38:54Z. The update package is 328.8 MB. This is a delta (partial) update that requires 12.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 49410e1b43abb6d1a8e797dd751ad7d165a30819.zip.