iOS 9.9.11.2.1 (build 15C153) is an official Apple over-the-air update for the iPhone 6, released on 2017-12-13T18:12:54Z. The update package is 1.39 GB. This is a delta (partial) update that requires 9.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c47defa3e95a496fb85f6fd6fea5025970d0a8da.zip.