watchOS 5.3 (build 16U569) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-07-22T19:17:40Z. The update package is 853.81 MB. This is a delta (partial) update that requires 4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 4d9ff35274e93adc32bcb84380db5b31bce46bb1.zip.