watchOS 5.3.8 (build 16U680) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2020-07-15T17:28:12Z. The update package is 46.29 MB. This is a delta (partial) update that requires 5.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ee4be82b5abcc7f692e8edb491ff31fc9a38429f.zip.