iOS 9.9.11.3.1 (build 15E302) is an official Apple over-the-air update for the iPhone 6s, released on 2018-04-24T17:10:36Z. The update package is 1.48 GB. This is a delta (partial) update that requires 9.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 4ed1cb376e41e79873d46d1ad3d83e5e3568fef4.zip.