watchOS 5.0 (build 16R5303d) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-06-19T17:36:38Z. The update package is 607.12 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: 6306da8e16fcfe616366ffe67b38bc3c0a9a3c48.zip.