iOS 9.9.13.3.1 (build 17D5050a) is an official Apple over-the-air update for the iPhone 6s+, released on 2020-01-22T18:07:29Z. The update package is 2.84 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: 523828da380bf04568114aade81efd4f95bed50c.zip.