iOS 13.4 (build 17E5255a) is an official Apple over-the-air update for the iPhone 6s, released on 2020-03-10T17:21:30Z. The update package is 711.08 MB. This is a delta (partial) update that requires 13.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0a75e022cd795bbcaeec878b988f723e8c4ba33c.zip.