watchOS 5.3.9 (build 16U693) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2020-11-05T18:19:42Z. The update package is 57.23 MB. This is a delta (partial) update that requires 5.3.6 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 5c64aaca904650975f31928f2cd226a81903ec09.zip.