watchOS 5.0 (build 16R5283q) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-06-05T09:53:02Z. The update package is 603.04 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: 3a598abc21c359b4c15c4bd2b08bc8d68301f606.zip.