watchOS 5.0 (build 16R5349a) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-08-13T17:06:42Z. The update package is 493.9 MB. This is a delta (partial) update that requires 4.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 11e70e051bac012546a4faa3b67dd59e27d96d36.zip.