iOS 12.0 (build 16A5357b) is an official Apple over-the-air update for the iPhone 6s, released on 2018-08-15T17:07:02Z. The update package is 1.21 GB. This is a delta (partial) update that requires 11.4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 44079aa4dc7d86f0380451ee9b6d658fe9cd52a2.zip.