watchOS 5.0 (build 16R364) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2018-09-12T19:19:09Z. The update package is 773.6 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: ce73047d66806ce2a9c2d212292d578b4c548751.zip.