watchOS 5.3.4 (build 16U627) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-12-10T18:22:29Z. The update package is 54.1 MB. This is a delta (partial) update that requires 5.3.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c00a7134846775691dadabfc89aff38580fd391e.zip.