watchOS 5.3 (build 16U569) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-07-22T19:19:53Z. The update package is 143.99 MB. This is a delta (partial) update that requires 5.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 01cfc7231948763ed48afb2d37b89823b92d19c3.zip.