watchOS 5.0 (build 16R5313d) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-07-03T17:11:21Z. The update package is 607.34 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: 9b2935d099db413bb4928308c09b5ef6f78bae1e.zip.