iOS 12.4 (build 16G5027g) is an official Apple over-the-air update for the iPhone 6s, released on 2019-05-15T17:05:45Z. The update package is 209.31 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: e02656e65c9a95ce4b9a3c35b2d46346d682dcfa.zip.