iOS 12.4 (build 16G5056d) is an official Apple over-the-air update for the iPhone 6s+, released on 2019-06-24T17:17:34Z. The update package is 196.11 MB. This is a delta (partial) update that requires 12.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5483f677b739fad418c0ea0e4fc4376efd2a114b.zip.