watchOS 5.3.9 (build 16U693) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2020-11-05T18:19:41Z. The update package is 61.79 MB. This is a delta (partial) update that requires 5.3.5 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: c2ddbce2d95b7443dfc5f3b5446d08a65ba246b9.zip.