watchOS 5.3.7 (build 16U674) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2020-05-18T17:31:45Z. The update package is 69.14 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: a27fe31386374a4fda623fe2eb97ca36e2e62834.zip.