watchOS 5.3.4 (build 16U627) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-12-10T18:22:25Z. The update package is 69.91 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ba3184b58279cb6e7688038ba6877444b69f5534.zip.