watchOS 4.0 (build 15R5365a) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-08-22T16:58:41Z. The update package is 204.47 MB. This is a delta (partial) update that requires 4.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 24d934410ac15e09629d6105cecb602c7cf4b7b9.zip.