iPadOS 12.4 (build 16G5056d) is an official Apple over-the-air update for the iPad Air (Cellular), released on 2019-06-24T17:16:47Z. The update package is 259.04 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: 361129d1549e1c6271661438ad6f929c93c53d8a.zip.