iOS 12.3 (build 16F5155a) is an official Apple over-the-air update for the iPhone 6s+, released on 2019-05-07T17:04:28Z. The update package is 64.96 MB. This is a delta (partial) update that requires 12.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8b9a70bd7cbc311dccada427e82a1a3f54503532.zip.