watchOS 5.0 (build 16R5283r) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-06-11T17:07:03Z. The update package is 545.85 MB. This is a delta (partial) update that requires 4.3.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8d139364d184776607c91af9bf652a5973a19626.zip.