watchOS 5.3.9 (build 16U693) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2020-12-14T18:08:34Z. The update package is 452.68 MB. This is a delta (partial) update that requires 5.1.3 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 9c1029ca405f745552be64dad4cb506b636ba2c4.zip.