iOS 12.0 (build 16A366) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-09-12T19:11:53Z. The update package is 1.38 GB. This is a delta (partial) update that requires 11.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9f985550defa41ba4297a0dcdb7296b364d87c07.zip.