iOS 12.1 (build 16B5084a) is an official Apple over-the-air update for the iPhone 6s+, released on 2018-10-15T17:03:33Z. The update package is 461.39 MB. This is a delta (partial) update that requires 12.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ef20724c1b127210471d8bbe5c43d5660d828509.zip.