watchOS 5.0 (build 16R5283q) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-06-05T09:52:57Z. The update package is 549.34 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: 7a9a0b1129aa40c69e4349430d588584e5b8fcca.zip.