watchOS 5.0 (build 16R5303d) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2018-06-19T17:36:48Z. The update package is 579.12 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: 4278486ed39dd275bbe3f9f9d93a6eb599d0a1b5.zip.