iOS 12.1 (build 16B5059d) is an official Apple over-the-air update for the iPhone 8 Plus (GSM), released on 2018-09-18T17:20:18Z. The update package is 550.72 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: af74b4088345cfbff1df428c89bef2bc68644320.zip.