iOS 9.9.12.1.1 (build 16C5043b) is an official Apple over-the-air update for the iPhone 6s, released on 2018-11-07T21:09:08Z. The update package is 2.15 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: 756cd1b99ed23f63bd3526cd8e8f54900ea61ce7.zip.