iOS 13.4 (build 17E5241d) is an official Apple over-the-air update for the iPhone 6s, released on 2020-02-26T18:17:55Z. The update package is 710.58 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: 08a4e7d5025f47fae457872bda9c7c03e993ff38.zip.