iOS 15.7.3 (build 19H307) is an official Apple over-the-air update for the iPhone 6s+, released on 2023-01-23T18:49:17Z. The update package is 3.12 GB. This is a delta (partial) update that requires 13.5.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1ffa8a4359ad473295c130d1d6de71b44f50a0b8.zip.