iOS 12.1 (build 16B5089b) is an official Apple over-the-air update for the iPhone 6s, released on 2018-10-22T17:02:06Z. The update package is 445.94 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: e676e93574b15b26970fe90437a31cb2f1f839e5.zip.