watchOS 5.0 (build 16R5303d) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-06-19T17:36:31Z. The update package is 564.81 MB. This is a delta (partial) update that requires 4.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a8e01ac76ee31da99ab84e7715a673491792902c.zip.