watchOS 5.0 (build 16R5322d) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-07-17T17:11:04Z. The update package is 646.21 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: e23be255b941f91deecf37b6590710a5b09ba089.zip.