watchOS 5.0 (build 16R5313d) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-07-03T17:11:09Z. The update package is 593.72 MB. This is a delta (partial) update that requires 4.2.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e7074df094ad628316061c8b0f6a2b3319f05cc2.zip.