iOS 9.9.15.3.1 (build 19D6052) is an official Apple over-the-air update for the iPhone 6s+, released on 2022-02-10T18:14:19Z. The update package is 3.97 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 174f62b77d87fa6ed4d0db16f3f4d1cda073720e.zip.