watchOS 5.0 (build 16R5322d) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2018-07-17T17:11:18Z. The update package is 672.38 MB. This is a delta (partial) update that requires 4.3.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d8d4ccf8af5711d774826da19f4a38672b2a3f4d.zip.