watchOS 5.3.7 (build 16U674) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2020-05-18T17:32:00Z. The update package is 50.01 MB. This is a delta (partial) update that requires 5.3.5 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d38f0d77077facf52881003e3dac84b5511760cc.zip.