watchOS 5.3 (build 16U569) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2019-07-22T17:20:24Z. The update package is 1004.45 MB. This is a delta (partial) update that requires 3.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9249e9da1e56446ad03cda1de2812e91c7cbe32a.zip.