watchOS 5.3 (build 16U569) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-07-22T19:18:22Z. The update package is 154.61 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: 55c2cb62ac387a4c6981e6b9eb50c8c5ee6456e8.zip.