iOS 9.9.11.2.1 (build 15C153) is an official Apple over-the-air update for the iPhone 6, released on 2017-12-13T18:12:53Z. The update package is 1.58 GB. This is a delta (partial) update that requires 8.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e819d9623ee74e316780d05805472227dfc10bc2.zip.