watchOS 5.0 (build 16R5349a) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2018-08-13T17:06:38Z. The update package is 489.64 MB. This is a delta (partial) update that requires 4.3.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a52042230f46e0cdc9f8689f716fe397f6a50ddc.zip.