iOS 15.7.3 (build 19H307) is an official Apple over-the-air update for the iPhone 6s+, released on 2023-01-23T18:49:20Z. The update package is 1.18 GB. This is a delta (partial) update that requires 15.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e0fb24636f7165f348149e98a3385bf29be5e907.zip.