watchOS 5.3 (build 16U5545c) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2019-06-11T17:13:18Z. The update package is 105.01 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: ba407d9fcb2ab1e9b0d21c40c16e50377b274328.zip.