iOS 9.3 (build 13E5191d) is an official Apple over-the-air update for the iPhone 6s+, released on 2016-01-25T20:52:50Z. The update package is 133.42 MB. This is a delta (partial) update that requires 9.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7c7166c643c1489c7ac5faefcf1ac861780ecf1b.zip.