watchOS 5.3 (build 16U5569a) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2019-07-16T17:14:08Z. The update package is 452.57 MB. This is a delta (partial) update that requires 5.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 82959bc032e2ca73b564157f23a1f45f20545185.zip.