iOS 12.4 (build 16G5038d) is an official Apple over-the-air update for the iPhone 6, released on 2019-05-28T17:07:46Z. The update package is 230.93 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: 318d9526fc708255c24430d1e8b8cbcffa807135.zip.