watchOS 5.0 (build 16R5313d) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2018-07-03T17:11:06Z. The update package is 567.76 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: 823447f29ed1c5be6d3ecd68e82510ae75bc2571.zip.