iOS 13.1 (build 17A5831c) is an official Apple over-the-air update for the iPhone 6s, released on 2019-09-04T17:06:19Z. The update package is 429.55 MB. This is a delta (partial) update that requires 13.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 89e330a4960f8b29bb2f8a9b25039132e32f03bc.zip.