watchOS 5.3.7 (build 16U674) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2020-05-18T17:31:59Z. The update package is 54.49 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: 504a64e0e8a69e0ff6d229ee5da40cc9cbc6f411.zip.