iOS 12.1 (build 16B92) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-10-30T17:17:09Z. The update package is 1.42 GB. This is a delta (partial) update that requires 11.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b71a3e5cd8671d9afed2fddd9c359e71601692fb.zip.