iOS 12.0 (build 16A5288q) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-06-05T09:52:42Z. The update package is 1.19 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: 3569c4924d9a6e730f6d784e58f69558eae4d228.zip.