watchOS 5.0 (build 16R5313d) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-07-03T17:11:13Z. The update package is 568.46 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: a8d41a8a70b554729b93df38d1d9df5cc182f5b5.zip.