iOS 12.1 (build 16B5089b) is an official Apple over-the-air update for the iPhone 8 Plus (GSM), released on 2018-10-22T17:01:55Z. The update package is 585.06 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: 7a91c84e1e99d6fbf57c0baadfd01ff8b09def93.zip.