watchOS 5.3 (build 16U6569) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-07-22T19:20:05Z. The update package is 66.55 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7270dc9ec7354b3eed510659b8d1e243e424a6fd.zip.