iOS 12.1 (build 16B92) is an official Apple over-the-air update for the iPhone 6+, released on 2018-10-30T17:16:47Z. The update package is 1.34 GB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 53ad3f87393d996d263f78913b1c2adc015900f1.zip.