iOS 13.1 (build 17A5837a) is an official Apple over-the-air update for the iPhone 8 (GSM), released on 2019-09-10T20:22:33Z. The update package is 247.29 MB. This is a delta (partial) update that requires 13.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5d5cf9792dab2636f162623fb6eb894958c6fa05.zip.