watchOS 9.0 (build 14S452) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2016-09-21T17:00:40Z. The update package is 797.75 MB. This is a delta (partial) update that requires 8.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 57e30eddbda3116357d051a2237f22d6f18cff91.zip.