watchOS 5.3 (build 16U6569) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-07-22T19:20:00Z. The update package is 114.36 MB. This is a delta (partial) update that requires 5.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1ded0038a02f9aa547b80e7a8cf79905947397d8.zip.