watchOS 5.0 (build 16R5349a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-08-13T17:06:47Z. The update package is 539.34 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: 3c1200a35732e3a30a72bf1cceec88f096de1045.zip.