watchOS 5.0 (build 16R5363a) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2018-08-31T17:15:29Z. The update package is 655.03 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: 1eb4ba60db9c6ba71fcceb990f522d7c584892ba.zip.